Year 5 Equivalent Fractions and Mixed Numbers: worked examples and questions with answers
By the end of this chapter you will be able to
- Find equivalent fractions with bars, number lines and by multiplying or dividing the top and the bottom by the same number, including tenths and hundredths
- Simplify a fraction by dividing the top and the bottom by a common factor
- Compare and order fractions (and mixed numbers) by changing them to a common denominator
- Change improper fractions into mixed numbers and mixed numbers into improper fractions, and see a fraction as a division
- Add and subtract fractions whose denominators are the same or multiples of one another
- Add and subtract mixed numbers, with and without crossing a whole number
- Multiply fractions and mixed numbers by whole numbers, and find fractions of amounts
- Solve word problems with bar models and explain your reasoning
You should already know
- Fractions of shapes, sets and amounts, and equivalent fractions in Year 4 (Year 4 Chapter 5)
- Adding and subtracting fractions with the same denominator
- Times tables and division facts to 12 × 12
- Factors and multiples (Year 5 Chapter 3)
Where this leads
- Decimals and percentages: tenths and hundredths as decimals (Chapter 7)
- Measures with fractions and decimals (Chapter 8)
- Adding and subtracting fractions with any denominators, and multiplying and dividing fractions in Year 6
National Curriculum for England, Key Stage 2 mathematics, Year 5. Content: Compare and order fractions whose denominators are all multiples of the same number, Identify, name and write equivalent fractions of a given fraction, represented visually, including tenths and hundredths, Recognise mixed numbers and improper fractions and convert from one form to the other, and write mathematical statements > 1 as a mixed number (e.g. 2/5 + 4/5 = 6/5 = 1 1/5), Add and subtract fractions with the same denominator and denominators that are multiples of the same number, Multiply proper fractions and mixed numbers by whole numbers, supported by materials and diagrams.
- 6.1 Equivalent fractions: Worksheet (PDF) · Answers (PDF) · lesson page
- 6.2 Simplifying fractions: Worksheet (PDF) · Answers (PDF) · lesson page
- 6.3 Comparing and ordering fractions: Worksheet (PDF) · Answers (PDF) · lesson page
- 6.4 Improper fractions and mixed numbers: Worksheet (PDF) · Answers (PDF) · lesson page
- 6.5 Adding and subtracting fractions: Worksheet (PDF) · Answers (PDF) · lesson page
- 6.6 Adding and subtracting mixed numbers: Worksheet (PDF) · Answers (PDF) · lesson page
- 6.7 Multiplying fractions by whole numbers and fractions of amounts: Worksheet (PDF) · Answers (PDF) · lesson page
- Check-up and SATs-style questions: Worksheet (PDF) · Answers (PDF) · lesson page
Exercise P Do you remember?
Non-calculatorKey words. The denominator (bottom number) tells us how many equal parts the whole is cut into. The numerator (top number) tells us how many parts we have.
Method. A fraction names equal parts of a whole. The bottom number is all the parts. The top number is the shaded parts.
- Count all the equal parts. This is the denominator (bottom number).There are 8 equal parts.
- Count the shaded parts. This is the numerator (top number).3 parts are shaded.
- Write the fraction.
3 8
Check. 3 shaded + 5 white = 8 parts. ✓
Watch out. Count all the parts, not just the white ones, for the bottom number.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 5 tells us to cut the amount into 5 equal parts. One part is
of the amount.1 5 30 ÷ 5 = 6 - Multiply by the numerator. The numerator 2 tells us how many of those parts we want.2 × 6 = 12
- Write the answer.
of 30 = 122 5
Check. Other way: 2 × 30 = 60, then ÷ 5 = 12. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 2 by to get 8? This tells us how the fraction has been changed. We must do the same to the other number.2 × 4 = 8, so the multiplier is 4.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 4.1 × 4 = 4
- Write the equivalent fractions. Now both numbers are filled in.
=1 2 4 8
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 9, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+5 9 =3 9 =5 + 3 9 8 9 - Write the answer. It is already in its simplest form.
8 9
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count the equal steps from the nearest whole number (or from 0).
- Find the whole numbers either side. The point is between two whole numbers.It is between 1 and 2.
- Count the small steps. Each step is
. There are 4 equal steps between each pair of whole numbers.1 4 From 1 it is 3 steps along, so it is 3 quarters more than 1. - Write it as a mixed number and as an improper fraction. 1 wholes are 4 quarters. Add 3 more.1
=3 4 7 4
Check. 1 × 4 + 3 = 7. ✓
Watch out. Count the steps between the numbers, not the tick marks. There is one more tick mark than there are steps.
Equivalent fractions
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
Equivalent fractions are different fractions that are worth the same amount. Half a pizza is the same amount of pizza as two quarters or four eighths. Look at the bars. They are all the same length. In each bar the shaded part ends at the same place, so
Why does it work? When you cut every part of a bar into 2 smaller equal parts, there are twice as many parts (the bottom number doubles) and you shade twice as many parts (the top number doubles). The amount shaded has not changed. So the rule is: multiply the top and the bottom by the same number. You can also divide the top and the bottom by the same number, as long as both numbers divide exactly.
Tenths and hundredths. A hundred square is cut into 100 small squares. Each row is one tenth, and each row has 10 small squares. So 1 tenth is the same as 10 hundredths. This means
Key ideas
- Equivalent fractions show the same amount.
- To make an equivalent fraction, multiply the top and the bottom by the same number:
=2 3 =2 × 4 3 × 4 .8 12 - You can also divide the top and the bottom by the same number:
=6 9 .2 3 - 1 tenth = 10 hundredths, so
=7 10 .70 100 - Equivalent fractions are at the same point on a number line.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 3 by to get 12? This tells us how the fraction has been changed. We must do the same to the other number.3 × 4 = 12, so the multiplier is 4.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 4.2 × 4 = 8
- Write the equivalent fractions. Now both numbers are filled in.
=2 3 8 12
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the top numbers. What do we multiply 3 by to get 9? This tells us how the fraction has been changed. We must do the same to the other number.3 × 3 = 9, so the multiplier is 3.
- Do the same to the bottom number. To keep the fraction the same size, the top and the bottom must both be multiplied by 3.4 × 3 = 12
- Write the equivalent fractions. Now both numbers are filled in.
=3 4 9 12
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by divideing the top and the bottom by the same number.
- Look at the bottom numbers. What do we divide 16 by to get 4? This tells us how the fraction has been changed. We must do the same to the other number.16 ÷ 4 = 4, so the divider is 4.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be divided by 4.12 ÷ 4 = 3
- Write the equivalent fractions. Now both numbers are filled in.
=12 16 3 4
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 10 by to get 100? This tells us how the fraction has been changed. We must do the same to the other number.10 × 10 = 100, so the multiplier is 10.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 10.3 × 10 = 30
- Write the equivalent fractions. Now both numbers are filled in.
=3 10 30 100
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by divideing the top and the bottom by the same number.
- Look at the bottom numbers. What do we divide 100 by to get 10? This tells us how the fraction has been changed. We must do the same to the other number.100 ÷ 10 = 10, so the divider is 10.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be divided by 10.40 ÷ 10 = 4
- Write the equivalent fractions. Now both numbers are filled in.
=40 100 4 10
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the top numbers. What do we multiply 5 by to get 35? This tells us how the fraction has been changed. We must do the same to the other number.5 × 7 = 35, so the multiplier is 7.
- Do the same to the bottom number. To keep the fraction the same size, the top and the bottom must both be multiplied by 7.6 × 7 = 42
- Write the equivalent fractions. Now both numbers are filled in.
=5 6 35 42
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Multiply the top and the bottom of the fraction by the same number each time. Every answer is an equivalent fraction.
- Multiply the top and the bottom by 2. Multiplying both numbers by 2 cuts every part into 2 smaller equal parts, so the amount stays the same.
=2 5 =2 × 2 5 × 2 4 10 - Multiply the top and the bottom by 3. Multiplying both numbers by 3 cuts every part into 3 smaller equal parts, so the amount stays the same.
=2 5 =2 × 3 5 × 3 6 15 - Multiply the top and the bottom by 4. Multiplying both numbers by 4 cuts every part into 4 smaller equal parts, so the amount stays the same.
=2 5 =2 × 4 5 × 4 8 20 - Write your list. These fractions are all equivalent to the first one.
,4 10 ,6 15 8 20
Check. Each one simplifies back to
Watch out. Multiply the top and the bottom. Adding the same number to both changes the value.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Write both fractions in their simplest form. If the simplest forms are the same, the fractions are equivalent.
- Write
in its simplest form. Divide the top and the bottom by their highest common factor. If both are already as small as possible, leave them.6 9 =6 9 =6 ÷ 3 9 ÷ 3 2 3 - Write
in its simplest form. Do the same for the other fraction.4 6 =4 6 =4 ÷ 2 6 ÷ 2 2 3 - Compare the simplest forms. Equivalent fractions have the same simplest form.
and2 3 are the same, so the fractions are equivalent.2 3
Check. As a picture: both bars shade the same amount. ✓
Watch out. Do not just look at the numbers. 4/6 and 6/9 look different but are equivalent.
Watch out
Never add the same number to the top and the bottom.Exercise 6A Equivalent fractions
Non-calculatorKey words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 3 by to get 6? This tells us how the fraction has been changed. We must do the same to the other number.3 × 2 = 6, so the multiplier is 2.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 2.1 × 2 = 2
- Write the equivalent fractions. Now both numbers are filled in.
=1 3 2 6
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 4 by to get 12? This tells us how the fraction has been changed. We must do the same to the other number.4 × 3 = 12, so the multiplier is 3.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 3.3 × 3 = 9
- Write the equivalent fractions. Now both numbers are filled in.
=3 4 9 12
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by divideing the top and the bottom by the same number.
- Look at the top numbers. What do we divide 4 by to get 2? This tells us how the fraction has been changed. We must do the same to the other number.4 ÷ 2 = 2, so the divider is 2.
- Do the same to the bottom number. To keep the fraction the same size, the top and the bottom must both be divided by 2.10 ÷ 2 = 5
- Write the equivalent fractions. Now both numbers are filled in.
=4 10 2 5
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 3 by to get 6? This tells us how the fraction has been changed. We must do the same to the other number.3 × 2 = 6, so the multiplier is 2.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 2.1 × 2 = 2
- Write the equivalent fractions. Now both numbers are filled in.
=1 3 2 6
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 5 by to get 10? This tells us how the fraction has been changed. We must do the same to the other number.5 × 2 = 10, so the multiplier is 2.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 2.2 × 2 = 4
- Write the equivalent fractions. Now both numbers are filled in.
=2 5 4 10
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 4 by to get 12? This tells us how the fraction has been changed. We must do the same to the other number.4 × 3 = 12, so the multiplier is 3.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 3.3 × 3 = 9
- Write the equivalent fractions. Now both numbers are filled in.
=3 4 9 12
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 6 by to get 18? This tells us how the fraction has been changed. We must do the same to the other number.6 × 3 = 18, so the multiplier is 3.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 3.5 × 3 = 15
- Write the equivalent fractions. Now both numbers are filled in.
=5 6 15 18
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 10 by to get 100? This tells us how the fraction has been changed. We must do the same to the other number.10 × 10 = 100, so the multiplier is 10.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 10.7 × 10 = 70
- Write the equivalent fractions. Now both numbers are filled in.
=7 10 70 100
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 9 by to get 27? This tells us how the fraction has been changed. We must do the same to the other number.9 × 3 = 27, so the multiplier is 3.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 3.4 × 3 = 12
- Write the equivalent fractions. Now both numbers are filled in.
=4 9 12 27
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the top numbers. What do we multiply 2 by to get 8? This tells us how the fraction has been changed. We must do the same to the other number.2 × 4 = 8, so the multiplier is 4.
- Do the same to the bottom number. To keep the fraction the same size, the top and the bottom must both be multiplied by 4.3 × 4 = 12
- Write the equivalent fractions. Now both numbers are filled in.
=2 3 8 12
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the top numbers. What do we multiply 3 by to get 12? This tells us how the fraction has been changed. We must do the same to the other number.3 × 4 = 12, so the multiplier is 4.
- Do the same to the bottom number. To keep the fraction the same size, the top and the bottom must both be multiplied by 4.5 × 4 = 20
- Write the equivalent fractions. Now both numbers are filled in.
=3 5 12 20
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the top numbers. What do we multiply 5 by to get 15? This tells us how the fraction has been changed. We must do the same to the other number.5 × 3 = 15, so the multiplier is 3.
- Do the same to the bottom number. To keep the fraction the same size, the top and the bottom must both be multiplied by 3.8 × 3 = 24
- Write the equivalent fractions. Now both numbers are filled in.
=5 8 15 24
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the top numbers. What do we multiply 7 by to get 70? This tells us how the fraction has been changed. We must do the same to the other number.7 × 10 = 70, so the multiplier is 10.
- Do the same to the bottom number. To keep the fraction the same size, the top and the bottom must both be multiplied by 10.10 × 10 = 100
- Write the equivalent fractions. Now both numbers are filled in.
=7 10 70 100
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the top numbers. What do we multiply 1 by to get 5? This tells us how the fraction has been changed. We must do the same to the other number.1 × 5 = 5, so the multiplier is 5.
- Do the same to the bottom number. To keep the fraction the same size, the top and the bottom must both be multiplied by 5.4 × 5 = 20
- Write the equivalent fractions. Now both numbers are filled in.
=1 4 5 20
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the top numbers. What do we multiply 3 by to get 21? This tells us how the fraction has been changed. We must do the same to the other number.3 × 7 = 21, so the multiplier is 7.
- Do the same to the bottom number. To keep the fraction the same size, the top and the bottom must both be multiplied by 7.7 × 7 = 49
- Write the equivalent fractions. Now both numbers are filled in.
=3 7 21 49
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by divideing the top and the bottom by the same number.
- Look at the bottom numbers. What do we divide 8 by to get 4? This tells us how the fraction has been changed. We must do the same to the other number.8 ÷ 2 = 4, so the divider is 2.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be divided by 2.6 ÷ 2 = 3
- Write the equivalent fractions. Now both numbers are filled in.
=6 8 3 4
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by divideing the top and the bottom by the same number.
- Look at the bottom numbers. What do we divide 15 by to get 3? This tells us how the fraction has been changed. We must do the same to the other number.15 ÷ 5 = 3, so the divider is 5.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be divided by 5.10 ÷ 5 = 2
- Write the equivalent fractions. Now both numbers are filled in.
=10 15 2 3
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by divideing the top and the bottom by the same number.
- Look at the bottom numbers. What do we divide 16 by to get 4? This tells us how the fraction has been changed. We must do the same to the other number.16 ÷ 4 = 4, so the divider is 4.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be divided by 4.12 ÷ 4 = 3
- Write the equivalent fractions. Now both numbers are filled in.
=12 16 3 4
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by divideing the top and the bottom by the same number.
- Look at the bottom numbers. What do we divide 100 by to get 10? This tells us how the fraction has been changed. We must do the same to the other number.100 ÷ 10 = 10, so the divider is 10.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be divided by 10.40 ÷ 10 = 4
- Write the equivalent fractions. Now both numbers are filled in.
=40 100 4 10
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by divideing the top and the bottom by the same number.
- Look at the top numbers. What do we divide 9 by to get 3? This tells us how the fraction has been changed. We must do the same to the other number.9 ÷ 3 = 3, so the divider is 3.
- Do the same to the bottom number. To keep the fraction the same size, the top and the bottom must both be divided by 3.12 ÷ 3 = 4
- Write the equivalent fractions. Now both numbers are filled in.
=9 12 3 4
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by divideing the top and the bottom by the same number.
- Look at the top numbers. What do we divide 20 by to get 2? This tells us how the fraction has been changed. We must do the same to the other number.20 ÷ 10 = 2, so the divider is 10.
- Do the same to the bottom number. To keep the fraction the same size, the top and the bottom must both be divided by 10.50 ÷ 10 = 5
- Write the equivalent fractions. Now both numbers are filled in.
=20 50 2 5
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. The denominator (bottom number) tells us how many equal parts the whole is cut into. The numerator (top number) tells us how many parts we have.
Method. Each row of the hundred square is one tenth. 1 tenth is 10 hundredths.
- Count the shaded small squares. There are 100 small squares in the whole, so the denominator is 100.30 shaded squares, so 30 out of 100.
- Write the fraction.
30 100
Check. 3 full rows of 10 = 30 squares. ✓
Watch out. The whole square is 100 small squares, not 10.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by divideing the top and the bottom by the same number.
- Look at the bottom numbers. What do we divide 100 by to get 10? This tells us how the fraction has been changed. We must do the same to the other number.100 ÷ 10 = 10, so the divider is 10.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be divided by 10.30 ÷ 10 = 3
- Write the equivalent fractions. Now both numbers are filled in.
=30 100 3 10
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 10 by to get 100? This tells us how the fraction has been changed. We must do the same to the other number.10 × 10 = 100, so the multiplier is 10.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 10.7 × 10 = 70
- Write the equivalent fractions. Now both numbers are filled in.
=7 10 70 100
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by divideing the top and the bottom by the same number.
- Look at the bottom numbers. What do we divide 100 by to get 10? This tells us how the fraction has been changed. We must do the same to the other number.100 ÷ 10 = 10, so the divider is 10.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be divided by 10.60 ÷ 10 = 6
- Write the equivalent fractions. Now both numbers are filled in.
=60 100 6 10
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 2 by to get 10? This tells us how the fraction has been changed. We must do the same to the other number.2 × 5 = 10, so the multiplier is 5.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 5.1 × 5 = 5
- Write the equivalent fractions. Now both numbers are filled in.
=1 2 5 10
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 5 by to get 10? This tells us how the fraction has been changed. We must do the same to the other number.5 × 2 = 10, so the multiplier is 2.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 2.3 × 2 = 6
- Write the equivalent fractions. Now both numbers are filled in.
=3 5 6 10
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 10 by to get 100? This tells us how the fraction has been changed. We must do the same to the other number.10 × 10 = 100, so the multiplier is 10.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 10.9 × 10 = 90
- Write the equivalent fractions. Now both numbers are filled in.
=9 10 90 100
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 4 by to get 100? This tells us how the fraction has been changed. We must do the same to the other number.4 × 25 = 100, so the multiplier is 25.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 25.1 × 25 = 25
- Write the equivalent fractions. Now both numbers are filled in.
=1 4 25 100
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Multiply the top and the bottom of the fraction by the same number each time. Every answer is an equivalent fraction.
- Multiply the top and the bottom by 2. Multiplying both numbers by 2 cuts every part into 2 smaller equal parts, so the amount stays the same.
=1 4 =1 × 2 4 × 2 2 8 - Multiply the top and the bottom by 3. Multiplying both numbers by 3 cuts every part into 3 smaller equal parts, so the amount stays the same.
=1 4 =1 × 3 4 × 3 3 12 - Multiply the top and the bottom by 4. Multiplying both numbers by 4 cuts every part into 4 smaller equal parts, so the amount stays the same.
=1 4 =1 × 4 4 × 4 4 16 - Write your list. These fractions are all equivalent to the first one.
,2 8 ,3 12 4 16
Check. Each one simplifies back to
Watch out. Multiply the top and the bottom. Adding the same number to both changes the value.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Multiply the top and the bottom of the fraction by the same number each time. Every answer is an equivalent fraction.
- Multiply the top and the bottom by 2. Multiplying both numbers by 2 cuts every part into 2 smaller equal parts, so the amount stays the same.
=2 3 =2 × 2 3 × 2 4 6 - Multiply the top and the bottom by 3. Multiplying both numbers by 3 cuts every part into 3 smaller equal parts, so the amount stays the same.
=2 3 =2 × 3 3 × 3 6 9 - Multiply the top and the bottom by 4. Multiplying both numbers by 4 cuts every part into 4 smaller equal parts, so the amount stays the same.
=2 3 =2 × 4 3 × 4 8 12 - Write your list. These fractions are all equivalent to the first one.
,4 6 ,6 9 8 12
Check. Each one simplifies back to
Watch out. Multiply the top and the bottom. Adding the same number to both changes the value.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Multiply the top and the bottom of the fraction by the same number each time. Every answer is an equivalent fraction.
- Multiply the top and the bottom by 2. Multiplying both numbers by 2 cuts every part into 2 smaller equal parts, so the amount stays the same.
=3 5 =3 × 2 5 × 2 6 10 - Multiply the top and the bottom by 3. Multiplying both numbers by 3 cuts every part into 3 smaller equal parts, so the amount stays the same.
=3 5 =3 × 3 5 × 3 9 15 - Multiply the top and the bottom by 4. Multiplying both numbers by 4 cuts every part into 4 smaller equal parts, so the amount stays the same.
=3 5 =3 × 4 5 × 4 12 20 - Write your list. These fractions are all equivalent to the first one.
,6 10 ,9 15 12 20
Check. Each one simplifies back to
Watch out. Multiply the top and the bottom. Adding the same number to both changes the value.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 3 by to get 6? This tells us how the fraction has been changed. We must do the same to the other number.3 × 2 = 6, so the multiplier is 2.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 2.2 × 2 = 4
- Write the equivalent fractions. Now both numbers are filled in.
=2 3 4 6
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 3 by to get 12? This tells us how the fraction has been changed. We must do the same to the other number.3 × 4 = 12, so the multiplier is 4.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 4.2 × 4 = 8
- Write the equivalent fractions. Now both numbers are filled in.
=2 3 8 12
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Write both fractions in their simplest form. If the simplest forms are the same, the fractions are equivalent.
- Write
in its simplest form. Divide the top and the bottom by their highest common factor. If both are already as small as possible, leave them.3 4 is already in its simplest form.3 4 - Write
in its simplest form. Do the same for the other fraction.9 12 =9 12 =9 ÷ 3 12 ÷ 3 3 4 - Compare the simplest forms. Equivalent fractions have the same simplest form.
and3 4 are the same, so the fractions are equivalent.3 4
Check. As a picture: both bars shade the same amount. ✓
Watch out. Do not just look at the numbers. 4/6 and 6/9 look different but are equivalent.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Write both fractions in their simplest form. If the simplest forms are the same, the fractions are equivalent.
- Write
in its simplest form. Divide the top and the bottom by their highest common factor. If both are already as small as possible, leave them.2 5 is already in its simplest form.2 5 - Write
in its simplest form. Do the same for the other fraction.4 15 is already in its simplest form.4 15 - Compare the simplest forms. Equivalent fractions have the same simplest form.
and2 5 are different, so the fractions are not equivalent.4 15
Check.
Watch out. Do not just look at the numbers. 4/6 and 6/9 look different but are equivalent.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Write both fractions in their simplest form. If the simplest forms are the same, the fractions are equivalent.
- Write
in its simplest form. Divide the top and the bottom by their highest common factor. If both are already as small as possible, leave them.5 6 is already in its simplest form.5 6 - Write
in its simplest form. Do the same for the other fraction.10 12 =10 12 =10 ÷ 2 12 ÷ 2 5 6 - Compare the simplest forms. Equivalent fractions have the same simplest form.
and5 6 are the same, so the fractions are equivalent.5 6
Check. As a picture: both bars shade the same amount. ✓
Watch out. Do not just look at the numbers. 4/6 and 6/9 look different but are equivalent.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Write both fractions in their simplest form. If the simplest forms are the same, the fractions are equivalent.
- Write
in its simplest form. Divide the top and the bottom by their highest common factor. If both are already as small as possible, leave them.3 8 is already in its simplest form.3 8 - Write
in its simplest form. Do the same for the other fraction.6 12 =6 12 =6 ÷ 6 12 ÷ 6 1 2 - Compare the simplest forms. Equivalent fractions have the same simplest form.
and3 8 are different, so the fractions are not equivalent.1 2
Check.
Watch out. Do not just look at the numbers. 4/6 and 6/9 look different but are equivalent.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Work out the value of each one in its simplest form. Three will be the same. The odd one out is the one that is different.
- Write each one in its simplest form. Then equal values are easy to spot.
=2 4 1 2 =3 6 1 2 =4 10 2 5 =5 10 1 2 - Find the one that is different. The other three have the same value.
is the odd one out.4 10
Check. Check the three that match once more. ✓
Watch out. Compare values, not the look of the numbers.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Write each fraction in its simplest form.
- Write
in its simplest form. Then we know what to look for.3 4 =3 4 3 4 - Simplify each option. Divide the top and the bottom by their highest common factor.
=6 8 → equal3 4 =9 12 → equal3 4 =8 12 → not equal2 3 =12 16 → equal3 4 =15 24 → not equal5 8 - Pick the equal ones.
,6 8 ,9 12 12 16
Check. Multiply
Watch out. Check the top AND the bottom change by the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Change both fractions so they have the same denominator, or simplify one of them. Then compare.
- Look at what Ella ate. Ella ate 4 of the 8 equal slices.
4 8 - Look at what Sam ate. Sam ate 2 of 4 equal slices of a pizza the same size.
2 4 - Write both with the same denominator. Multiply the top and the bottom of
by 2.2 4 =2 4 =2 × 2 4 × 2 4 8 - Compare. The fractions are equal, so they ate the same amount.
=4 8 4 8
Check. Both are one half of a pizza. ✓
Watch out. Different numbers can still mean the same amount.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Work the question out yourself first. Then compare your working with the working in the question and find where it goes wrong.
- Work it out correctly. We need the right answer to compare with.
=2 3 =2 × 2 3 × 2 4 6 - Find the mistake. Leo added 2 to the top and 2 to the bottom (2 + 2 = 4 and 3 + 2 = 5). Adding changes the fraction. He should have multiplied both numbers by 2.Leo wrote
=2 3 .4 5 - Write the correct answer. The correct answer is
. (4 6 is bigger than4 5 .)2 3
Check.
Watch out. Multiply or divide the top and the bottom. Never add.
Key words. Always means true every time. Never means false every time. Sometimes means true for some numbers and false for others.
Method. Test the statement with some numbers. If it is always true, never true, or true for some numbers only, that gives the answer.
- Try some examples. Testing numbers helps us see if the statement is true every time.
: add 1 to the top and bottom →1 2 . These are not equal, because a half is smaller than two thirds.2 3 - Look for an example that does not work. One example that breaks the rule is a counter-example.
: add 1 to the top and bottom →3 3 . Both equal 1 whole, so this one works.4 4 - Decide: always, sometimes or never? It does not work for most fractions, but it does work for a fraction that is equal to 1.Sometimes
Check. We found one example that works and one that does not. ✓
Watch out. To show a statement is “always” true you need a reason. A few examples are not enough to prove it, but one counter-example shows it is not always true.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions of 2/3 are 2k/3k. The top and the bottom add to 5k, so work out what k must be.
- Add the top and the bottom of the first fraction. This is the total that gets multiplied.2 + 3 = 5
- Find the multiplier. We need the total to be 35. What do we multiply 5 by to get 35?5 × 7 = 35, so the multiplier is 7.
- Multiply the top and the bottom. Multiply both by 7.
=2 × 7 3 × 7 14 21 - Check the total. Add the new top and bottom.14 + 21 = 35
Check.
Watch out. The multiplier works on both numbers, so the total is multiplied too.
Simplifying fractions
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
The fraction
The best number to divide by is the highest common factor (HCF): the biggest number that goes into both. List the factors of the top and of the bottom. For 8 and 12: factors of 8 are 1, 2, 4, 8 and factors of 12 are 1, 2, 3, 4, 6, 12. The biggest in both lists is 4. So
Key ideas
- Simplify a fraction: divide the top and the bottom by the same common factor.
- The highest common factor does it in one step. Dividing in small steps works too.
- A fraction is in its simplest form when the only common factor of the top and bottom is 1.
- Simplifying does not change the value:
=8 12 .2 3 - In a story, write part over whole first. 12 of 30 children is
=12 30 .2 5
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 6 and of 8. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 6: 1, 2, 3, 6
Factors of 8: 1, 2, 4, 8
Common factors: 1, 2 - Pick the biggest common factor: 2. Divide the top and the bottom by 2. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=6 8 =6 ÷ 2 8 ÷ 2 3 4 - Check it is in its simplest form. If 3 and 4 still shared a factor, we could go on.The only common factor of 3 and 4 is 1, so
is the simplest form.3 4
Check. Multiply back: 3 × 2 = 6 and 4 × 2 = 8. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 12 and of 18. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 12: 1, 2, 3, 4, 6, 12
Factors of 18: 1, 2, 3, 6, 9, 18
Common factors: 1, 2, 3, 6 - Pick the biggest common factor: 6. Divide the top and the bottom by 6. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=12 18 =12 ÷ 6 18 ÷ 6 2 3 - Check it is in its simplest form. If 2 and 3 still shared a factor, we could go on.The only common factor of 2 and 3 is 1, so
is the simplest form.2 3
Check. Multiply back: 2 × 6 = 12 and 3 × 6 = 18. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 15 and of 25. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 15: 1, 3, 5, 15
Factors of 25: 1, 5, 25
Common factors: 1, 5 - Pick the biggest common factor: 5. Divide the top and the bottom by 5. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=15 25 =15 ÷ 5 25 ÷ 5 3 5 - Check it is in its simplest form. If 3 and 5 still shared a factor, we could go on.The only common factor of 3 and 5 is 1, so
is the simplest form.3 5
Check. Multiply back: 3 × 5 = 15 and 5 × 5 = 25. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 40 and of 100. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 40: 1, 2, 4, 5, 8, 10, 20, 40
Factors of 100: 1, 2, 4, 5, 10, 20, 25, 50, 100
Common factors: 1, 2, 4, 5, 10, 20 - Pick the biggest common factor: 20. Divide the top and the bottom by 20. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=40 100 =40 ÷ 20 100 ÷ 20 2 5 - Check it is in its simplest form. If 2 and 5 still shared a factor, we could go on.The only common factor of 2 and 5 is 1, so
is the simplest form.2 5
Check. Multiply back: 2 × 20 = 40 and 5 × 20 = 100. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 18 and of 24. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 18: 1, 2, 3, 6, 9, 18
Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24
Common factors: 1, 2, 3, 6 - Pick the biggest common factor: 6. Divide the top and the bottom by 6. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=18 24 =18 ÷ 6 24 ÷ 6 3 4 - Check it is in its simplest form. If 3 and 4 still shared a factor, we could go on.The only common factor of 3 and 4 is 1, so
is the simplest form.3 4
Check. Multiply back: 3 × 6 = 18 and 4 × 6 = 24. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. A fraction is in its simplest form when the only number that divides into both the top and the bottom is 1.
- List the factors of 7 and of 12. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 7: 1, 7
Factors of 12: 1, 2, 3, 4, 6, 12
Common factors: 1 - Look for a common factor bigger than 1. If the only common factor is 1, we cannot make the numbers smaller.The only common factor is 1, so
is already in its simplest form.7 12 - Write the answer.
7 12
Check. There is no whole number bigger than 1 that goes into both numbers. ✓
Watch out. Do not simplify just because the numbers are odd or even. Always look for a common factor.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- Write the fraction: the part over the whole. 12 of the 30 children walk to school. The part goes on top and the whole goes on the bottom.
12 30 - List the factors of 12 and of 30. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 12: 1, 2, 3, 4, 6, 12
Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30
Common factors: 1, 2, 3, 6 - Pick the biggest common factor: 6. Divide the top and the bottom by 6. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=12 30 =12 ÷ 6 30 ÷ 6 2 5 - Check it is in its simplest form. If 2 and 5 still shared a factor, we could go on.The only common factor of 2 and 5 is 1, so
is the simplest form.2 5
Check. Multiply back: 2 × 6 = 12 and 5 × 6 = 30. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by any common factor you can see. Keep going until no common factor is left.
- Both numbers can be divided by 2. 48 and 64 are both in the 2 times table, so 2 is a common factor.
=48 64 =48 ÷ 2 64 ÷ 2 24 32 - Both numbers can be divided by 2. 24 and 32 are both in the 2 times table, so 2 is a common factor.
=24 32 =24 ÷ 2 32 ÷ 2 12 16 - Both numbers can be divided by 2. 12 and 16 are both in the 2 times table, so 2 is a common factor.
=12 16 =12 ÷ 2 16 ÷ 2 6 8 - Both numbers can be divided by 2. 6 and 8 are both in the 2 times table, so 2 is a common factor.
=6 8 =6 ÷ 2 8 ÷ 2 3 4 - Check there is no common factor left. Stop when the only number that goes into both is 1.The only common factor of 3 and 4 is 1, so
is the simplest form.3 4
Check.
Watch out. You do not need the biggest common factor straight away. Small steps get there too.
Watch out
Divide the top and the bottom. If you take the same number away from both (Exercise 6B Simplifying fractions
Non-calculatorKey words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 2 and of 4. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 2: 1, 2
Factors of 4: 1, 2, 4
Common factors: 1, 2 - Pick the biggest common factor: 2. Divide the top and the bottom by 2. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=2 4 =2 ÷ 2 4 ÷ 2 1 2 - Check it is in its simplest form. If 1 and 2 still shared a factor, we could go on.The only common factor of 1 and 2 is 1, so
is the simplest form.1 2
Check. Multiply back: 1 × 2 = 2 and 2 × 2 = 4. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 4 and of 8. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 4: 1, 2, 4
Factors of 8: 1, 2, 4, 8
Common factors: 1, 2, 4 - Pick the biggest common factor: 4. Divide the top and the bottom by 4. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=4 8 =4 ÷ 4 8 ÷ 4 1 2 - Check it is in its simplest form. If 1 and 2 still shared a factor, we could go on.The only common factor of 1 and 2 is 1, so
is the simplest form.1 2
Check. Multiply back: 1 × 4 = 4 and 2 × 4 = 8. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 3 and of 12. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 3: 1, 3
Factors of 12: 1, 2, 3, 4, 6, 12
Common factors: 1, 3 - Pick the biggest common factor: 3. Divide the top and the bottom by 3. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=3 12 =3 ÷ 3 12 ÷ 3 1 4 - Check it is in its simplest form. If 1 and 4 still shared a factor, we could go on.The only common factor of 1 and 4 is 1, so
is the simplest form.1 4
Check. Multiply back: 1 × 3 = 3 and 4 × 3 = 12. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 2 and of 6. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 2: 1, 2
Factors of 6: 1, 2, 3, 6
Common factors: 1, 2 - Pick the biggest common factor: 2. Divide the top and the bottom by 2. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=2 6 =2 ÷ 2 6 ÷ 2 1 3 - Check it is in its simplest form. If 1 and 3 still shared a factor, we could go on.The only common factor of 1 and 3 is 1, so
is the simplest form.1 3
Check. Multiply back: 1 × 2 = 2 and 3 × 2 = 6. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 5 and of 10. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 5: 1, 5
Factors of 10: 1, 2, 5, 10
Common factors: 1, 5 - Pick the biggest common factor: 5. Divide the top and the bottom by 5. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=5 10 =5 ÷ 5 10 ÷ 5 1 2 - Check it is in its simplest form. If 1 and 2 still shared a factor, we could go on.The only common factor of 1 and 2 is 1, so
is the simplest form.1 2
Check. Multiply back: 1 × 5 = 5 and 2 × 5 = 10. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 4 and of 10. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 4: 1, 2, 4
Factors of 10: 1, 2, 5, 10
Common factors: 1, 2 - Pick the biggest common factor: 2. Divide the top and the bottom by 2. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=4 10 =4 ÷ 2 10 ÷ 2 2 5 - Check it is in its simplest form. If 2 and 5 still shared a factor, we could go on.The only common factor of 2 and 5 is 1, so
is the simplest form.2 5
Check. Multiply back: 2 × 2 = 4 and 5 × 2 = 10. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 3 and of 9. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 3: 1, 3
Factors of 9: 1, 3, 9
Common factors: 1, 3 - Pick the biggest common factor: 3. Divide the top and the bottom by 3. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=3 9 =3 ÷ 3 9 ÷ 3 1 3 - Check it is in its simplest form. If 1 and 3 still shared a factor, we could go on.The only common factor of 1 and 3 is 1, so
is the simplest form.1 3
Check. Multiply back: 1 × 3 = 3 and 3 × 3 = 9. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 5 and of 15. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 5: 1, 5
Factors of 15: 1, 3, 5, 15
Common factors: 1, 5 - Pick the biggest common factor: 5. Divide the top and the bottom by 5. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=5 15 =5 ÷ 5 15 ÷ 5 1 3 - Check it is in its simplest form. If 1 and 3 still shared a factor, we could go on.The only common factor of 1 and 3 is 1, so
is the simplest form.1 3
Check. Multiply back: 1 × 5 = 5 and 3 × 5 = 15. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 10 and of 25. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 10: 1, 2, 5, 10
Factors of 25: 1, 5, 25
Common factors: 1, 5 - Pick the biggest common factor: 5. Divide the top and the bottom by 5. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=10 25 =10 ÷ 5 25 ÷ 5 2 5 - Check it is in its simplest form. If 2 and 5 still shared a factor, we could go on.The only common factor of 2 and 5 is 1, so
is the simplest form.2 5
Check. Multiply back: 2 × 5 = 10 and 5 × 5 = 25. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 6 and of 15. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 6: 1, 2, 3, 6
Factors of 15: 1, 3, 5, 15
Common factors: 1, 3 - Pick the biggest common factor: 3. Divide the top and the bottom by 3. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=6 15 =6 ÷ 3 15 ÷ 3 2 5 - Check it is in its simplest form. If 2 and 5 still shared a factor, we could go on.The only common factor of 2 and 5 is 1, so
is the simplest form.2 5
Check. Multiply back: 2 × 3 = 6 and 5 × 3 = 15. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 14 and of 21. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 14: 1, 2, 7, 14
Factors of 21: 1, 3, 7, 21
Common factors: 1, 7 - Pick the biggest common factor: 7. Divide the top and the bottom by 7. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=14 21 =14 ÷ 7 21 ÷ 7 2 3 - Check it is in its simplest form. If 2 and 3 still shared a factor, we could go on.The only common factor of 2 and 3 is 1, so
is the simplest form.2 3
Check. Multiply back: 2 × 7 = 14 and 3 × 7 = 21. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 8 and of 20. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 8: 1, 2, 4, 8
Factors of 20: 1, 2, 4, 5, 10, 20
Common factors: 1, 2, 4 - Pick the biggest common factor: 4. Divide the top and the bottom by 4. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=8 20 =8 ÷ 4 20 ÷ 4 2 5 - Check it is in its simplest form. If 2 and 5 still shared a factor, we could go on.The only common factor of 2 and 5 is 1, so
is the simplest form.2 5
Check. Multiply back: 2 × 4 = 8 and 5 × 4 = 20. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 8 and of 12. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 8: 1, 2, 4, 8
Factors of 12: 1, 2, 3, 4, 6, 12
Common factors: 1, 2, 4 - Pick the biggest common factor: 4. Divide the top and the bottom by 4. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=8 12 =8 ÷ 4 12 ÷ 4 2 3 - Check it is in its simplest form. If 2 and 3 still shared a factor, we could go on.The only common factor of 2 and 3 is 1, so
is the simplest form.2 3
Check. Multiply back: 2 × 4 = 8 and 3 × 4 = 12. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 9 and of 15. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 9: 1, 3, 9
Factors of 15: 1, 3, 5, 15
Common factors: 1, 3 - Pick the biggest common factor: 3. Divide the top and the bottom by 3. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=9 15 =9 ÷ 3 15 ÷ 3 3 5 - Check it is in its simplest form. If 3 and 5 still shared a factor, we could go on.The only common factor of 3 and 5 is 1, so
is the simplest form.3 5
Check. Multiply back: 3 × 3 = 9 and 5 × 3 = 15. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 16 and of 24. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 16: 1, 2, 4, 8, 16
Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24
Common factors: 1, 2, 4, 8 - Pick the biggest common factor: 8. Divide the top and the bottom by 8. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=16 24 =16 ÷ 8 24 ÷ 8 2 3 - Check it is in its simplest form. If 2 and 3 still shared a factor, we could go on.The only common factor of 2 and 3 is 1, so
is the simplest form.2 3
Check. Multiply back: 2 × 8 = 16 and 3 × 8 = 24. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 18 and of 30. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 18: 1, 2, 3, 6, 9, 18
Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30
Common factors: 1, 2, 3, 6 - Pick the biggest common factor: 6. Divide the top and the bottom by 6. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=18 30 =18 ÷ 6 30 ÷ 6 3 5 - Check it is in its simplest form. If 3 and 5 still shared a factor, we could go on.The only common factor of 3 and 5 is 1, so
is the simplest form.3 5
Check. Multiply back: 3 × 6 = 18 and 5 × 6 = 30. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 20 and of 32. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 20: 1, 2, 4, 5, 10, 20
Factors of 32: 1, 2, 4, 8, 16, 32
Common factors: 1, 2, 4 - Pick the biggest common factor: 4. Divide the top and the bottom by 4. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=20 32 =20 ÷ 4 32 ÷ 4 5 8 - Check it is in its simplest form. If 5 and 8 still shared a factor, we could go on.The only common factor of 5 and 8 is 1, so
is the simplest form.5 8
Check. Multiply back: 5 × 4 = 20 and 8 × 4 = 32. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 24 and of 36. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24
Factors of 36: 1, 2, 3, 4, 6, 9, 12, 18, 36
Common factors: 1, 2, 3, 4, 6, 12 - Pick the biggest common factor: 12. Divide the top and the bottom by 12. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=24 36 =24 ÷ 12 36 ÷ 12 2 3 - Check it is in its simplest form. If 2 and 3 still shared a factor, we could go on.The only common factor of 2 and 3 is 1, so
is the simplest form.2 3
Check. Multiply back: 2 × 12 = 24 and 3 × 12 = 36. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 25 and of 100. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 25: 1, 5, 25
Factors of 100: 1, 2, 4, 5, 10, 20, 25, 50, 100
Common factors: 1, 5, 25 - Pick the biggest common factor: 25. Divide the top and the bottom by 25. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=25 100 =25 ÷ 25 100 ÷ 25 1 4 - Check it is in its simplest form. If 1 and 4 still shared a factor, we could go on.The only common factor of 1 and 4 is 1, so
is the simplest form.1 4
Check. Multiply back: 1 × 25 = 25 and 4 × 25 = 100. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 60 and of 100. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 60: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60
Factors of 100: 1, 2, 4, 5, 10, 20, 25, 50, 100
Common factors: 1, 2, 4, 5, 10, 20 - Pick the biggest common factor: 20. Divide the top and the bottom by 20. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=60 100 =60 ÷ 20 100 ÷ 20 3 5 - Check it is in its simplest form. If 3 and 5 still shared a factor, we could go on.The only common factor of 3 and 5 is 1, so
is the simplest form.3 5
Check. Multiply back: 3 × 20 = 60 and 5 × 20 = 100. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 45 and of 100. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 45: 1, 3, 5, 9, 15, 45
Factors of 100: 1, 2, 4, 5, 10, 20, 25, 50, 100
Common factors: 1, 5 - Pick the biggest common factor: 5. Divide the top and the bottom by 5. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=45 100 =45 ÷ 5 100 ÷ 5 9 20 - Check it is in its simplest form. If 9 and 20 still shared a factor, we could go on.The only common factor of 9 and 20 is 1, so
is the simplest form.9 20
Check. Multiply back: 9 × 5 = 45 and 20 × 5 = 100. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 75 and of 100. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 75: 1, 3, 5, 15, 25, 75
Factors of 100: 1, 2, 4, 5, 10, 20, 25, 50, 100
Common factors: 1, 5, 25 - Pick the biggest common factor: 25. Divide the top and the bottom by 25. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=75 100 =75 ÷ 25 100 ÷ 25 3 4 - Check it is in its simplest form. If 3 and 4 still shared a factor, we could go on.The only common factor of 3 and 4 is 1, so
is the simplest form.3 4
Check. Multiply back: 3 × 25 = 75 and 4 × 25 = 100. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 8 and of 100. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 8: 1, 2, 4, 8
Factors of 100: 1, 2, 4, 5, 10, 20, 25, 50, 100
Common factors: 1, 2, 4 - Pick the biggest common factor: 4. Divide the top and the bottom by 4. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=8 100 =8 ÷ 4 100 ÷ 4 2 25 - Check it is in its simplest form. If 2 and 25 still shared a factor, we could go on.The only common factor of 2 and 25 is 1, so
is the simplest form.2 25
Check. Multiply back: 2 × 4 = 8 and 25 × 4 = 100. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 36 and of 100. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 36: 1, 2, 3, 4, 6, 9, 12, 18, 36
Factors of 100: 1, 2, 4, 5, 10, 20, 25, 50, 100
Common factors: 1, 2, 4 - Pick the biggest common factor: 4. Divide the top and the bottom by 4. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=36 100 =36 ÷ 4 100 ÷ 4 9 25 - Check it is in its simplest form. If 9 and 25 still shared a factor, we could go on.The only common factor of 9 and 25 is 1, so
is the simplest form.9 25
Check. Multiply back: 9 × 4 = 36 and 25 × 4 = 100. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- Write the fraction shown by the bar. The bar has 12 equal parts and 8 are shaded.
8 12 - List the factors of 8 and of 12. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 8: 1, 2, 4, 8
Factors of 12: 1, 2, 3, 4, 6, 12
Common factors: 1, 2, 4 - Pick the biggest common factor: 4. Divide the top and the bottom by 4. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=8 12 =8 ÷ 4 12 ÷ 4 2 3 - Check it is in its simplest form. If 2 and 3 still shared a factor, we could go on.The only common factor of 2 and 3 is 1, so
is the simplest form.2 3
Check. Multiply back: 2 × 4 = 8 and 3 × 4 = 12. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. A fraction is in its simplest form when the only number that divides into both the top and the bottom is 1.
- List the factors of 4 and of 9. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 4: 1, 2, 4
Factors of 9: 1, 3, 9
Common factors: 1 - Look for a common factor bigger than 1. If the only common factor is 1, we cannot make the numbers smaller.The only common factor is 1, so
is already in its simplest form.4 9 - Write the answer.
4 9
Check. There is no whole number bigger than 1 that goes into both numbers. ✓
Watch out. Do not simplify just because the numbers are odd or even. Always look for a common factor.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 6 and of 10. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 6: 1, 2, 3, 6
Factors of 10: 1, 2, 5, 10
Common factors: 1, 2 - Pick the biggest common factor: 2. Divide the top and the bottom by 2. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=6 10 =6 ÷ 2 10 ÷ 2 3 5 - Check it is in its simplest form. If 3 and 5 still shared a factor, we could go on.The only common factor of 3 and 5 is 1, so
is the simplest form.3 5
Check. Multiply back: 3 × 2 = 6 and 5 × 2 = 10. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. A fraction is in its simplest form when the only number that divides into both the top and the bottom is 1.
- List the factors of 7 and of 15. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 7: 1, 7
Factors of 15: 1, 3, 5, 15
Common factors: 1 - Look for a common factor bigger than 1. If the only common factor is 1, we cannot make the numbers smaller.The only common factor is 1, so
is already in its simplest form.7 15 - Write the answer.
7 15
Check. There is no whole number bigger than 1 that goes into both numbers. ✓
Watch out. Do not simplify just because the numbers are odd or even. Always look for a common factor.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 9 and of 12. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 9: 1, 3, 9
Factors of 12: 1, 2, 3, 4, 6, 12
Common factors: 1, 3 - Pick the biggest common factor: 3. Divide the top and the bottom by 3. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=9 12 =9 ÷ 3 12 ÷ 3 3 4 - Check it is in its simplest form. If 3 and 4 still shared a factor, we could go on.The only common factor of 3 and 4 is 1, so
is the simplest form.3 4
Check. Multiply back: 3 × 3 = 9 and 4 × 3 = 12. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. A fraction is in its simplest form when the only number that divides into both the top and the bottom is 1.
- List the factors of 11 and of 20. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 11: 1, 11
Factors of 20: 1, 2, 4, 5, 10, 20
Common factors: 1 - Look for a common factor bigger than 1. If the only common factor is 1, we cannot make the numbers smaller.The only common factor is 1, so
is already in its simplest form.11 20 - Write the answer.
11 20
Check. There is no whole number bigger than 1 that goes into both numbers. ✓
Watch out. Do not simplify just because the numbers are odd or even. Always look for a common factor.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- Write the fraction: the part over the whole. The part is 12 and the whole class is 30. The part goes on top and the whole goes on the bottom.
12 30 - List the factors of 12 and of 30. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 12: 1, 2, 3, 4, 6, 12
Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30
Common factors: 1, 2, 3, 6 - Pick the biggest common factor: 6. Divide the top and the bottom by 6. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=12 30 =12 ÷ 6 30 ÷ 6 2 5 - Check it is in its simplest form. If 2 and 5 still shared a factor, we could go on.The only common factor of 2 and 5 is 1, so
is the simplest form.2 5
Check. Multiply back: 2 × 6 = 12 and 5 × 6 = 30. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- Write the fraction: the part over the whole. The part is 18 pages and the whole comic is 24 pages. The part goes on top and the whole goes on the bottom.
18 24 - List the factors of 18 and of 24. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 18: 1, 2, 3, 6, 9, 18
Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24
Common factors: 1, 2, 3, 6 - Pick the biggest common factor: 6. Divide the top and the bottom by 6. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=18 24 =18 ÷ 6 24 ÷ 6 3 4 - Check it is in its simplest form. If 3 and 4 still shared a factor, we could go on.The only common factor of 3 and 4 is 1, so
is the simplest form.3 4
Check. Multiply back: 3 × 6 = 18 and 4 × 6 = 24. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- Write the fraction: the part over the whole. The part is 15 stickers and the whole pack is 45. The part goes on top and the whole goes on the bottom.
15 45 - List the factors of 15 and of 45. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 15: 1, 3, 5, 15
Factors of 45: 1, 3, 5, 9, 15, 45
Common factors: 1, 3, 5, 15 - Pick the biggest common factor: 15. Divide the top and the bottom by 15. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=15 45 =15 ÷ 15 45 ÷ 15 1 3 - Check it is in its simplest form. If 1 and 3 still shared a factor, we could go on.The only common factor of 1 and 3 is 1, so
is the simplest form.1 3
Check. Multiply back: 1 × 15 = 15 and 3 × 15 = 45. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- Write the fraction: the part over the whole. The part is 20 cm and the whole ribbon is 50 cm. The part goes on top and the whole goes on the bottom.
20 50 - List the factors of 20 and of 50. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 20: 1, 2, 4, 5, 10, 20
Factors of 50: 1, 2, 5, 10, 25, 50
Common factors: 1, 2, 5, 10 - Pick the biggest common factor: 10. Divide the top and the bottom by 10. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=20 50 =20 ÷ 10 50 ÷ 10 2 5 - Check it is in its simplest form. If 2 and 5 still shared a factor, we could go on.The only common factor of 2 and 5 is 1, so
is the simplest form.2 5
Check. Multiply back: 2 × 10 = 20 and 5 × 10 = 50. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Write each fraction in its simplest form.
- Write
in its simplest form. Then we know what to look for.2 3 =2 3 2 3 - Simplify each option. Divide the top and the bottom by their highest common factor.
=8 12 → equal2 3 =10 15 → equal2 3 =6 10 → not equal3 5 =9 15 → not equal3 5 =14 21 → equal2 3 - Pick the equal ones.
,8 12 ,10 15 14 21
Check. Multiply
Watch out. Check the top AND the bottom change by the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 5 by to get 35? This tells us how the fraction has been changed. We must do the same to the other number.5 × 7 = 35, so the multiplier is 7.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 7.3 × 7 = 21
- Write the equivalent fractions. Now both numbers are filled in.
=3 5 21 35
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Work the question out yourself first. Then compare your working with the working in the question and find where it goes wrong.
- Work it out correctly. We need the right answer to compare with.
=10 15 =10 ÷ 5 15 ÷ 5 2 3 - Find the mistake. Tom subtracted 5 from the top and from the bottom (10 − 5 = 5 and 15 − 5 = 10). Taking away changes the fraction. He should have divided both by 5.Tom wrote
=10 15 .5 10 - Write the correct answer. The correct answer is
. (2 3 is one half, which is not the same as5 10 .)10 15
Check. 2 × 5 = 10 and 3 × 5 = 15. ✓
Watch out. Divide the top and the bottom. Never subtract.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Check whether the top and the bottom still share a common factor.
- Find the factors of 12 and of 18. We look for a common factor bigger than 1.Factors of 12: 1, 2, 3, 4, 6, 12
Factors of 18: 1, 2, 3, 6, 9, 18
Common factors: 1, 2, 3, 6 - Priya divided by 2 only.
÷ 2 =24 36 . But 12 and 18 still have common factors 2, 3 and 6.12 18 =12 18 =12 ÷ 6 18 ÷ 6 2 3 - Check the answer. The highest common factor of 24 and 36 is 12.
=24 36 =24 ÷ 12 36 ÷ 12 2 3
Check. The only common factor of 2 and 3 is 1. ✓
Watch out. After you simplify, always check again for a common factor.
Key words. Always means true every time. Never means false every time. Sometimes means true for some numbers and false for others.
Method. Test the statement with some numbers. If it is always true, never true, or true for some numbers only, that gives the answer.
- Try some examples. Testing numbers helps us see if the statement is true every time.
=2 4 (divide by 2)1 2 =6 10 (divide by 2)3 5 =14 16 (divide by 2)7 8 - Decide: always, sometimes or never? If the top and the bottom are both even, they are both in the 2 times table, so 2 is always a common factor.Always
Check. Each example was divided by 2. ✓
Watch out. To show a statement is “always” true you need a reason. A few examples are not enough to prove it, but one counter-example shows it is not always true.
Key words. Always means true every time. Never means false every time. Sometimes means true for some numbers and false for others.
Method. Test the statement with some numbers. If it is always true, never true, or true for some numbers only, that gives the answer.
- Try some examples. Testing numbers helps us see if the statement is true every time.
: factors of 3 are 1, 3 and factors of 7 are 1, 7. Only 1 is common.3 7 : only 1 is common.5 11 : only 1 is common.6 13 - Decide: always, sometimes or never? A prime number only has factors 1 and itself. In a proper fraction the top is smaller than the bottom, so the only common factor is 1.Never
Check. We cannot find a proper fraction like this that simplifies. ✓
Watch out. To show a statement is “always” true you need a reason. A few examples are not enough to prove it, but one counter-example shows it is not always true.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. A fraction is in its simplest form when the top and the bottom share no common factor except 1. Test each numerator from 1 to 11.
- List the factors of 12. Any numerator that shares a factor with 12 can be simplified.Factors of 12: 1, 2, 3, 4, 6, 12
- Test each numerator from 1 to 11. Cross out the ones that share a factor (2, 3, 4 or 6) with 12.1: only 1 is common → keep
2: common factor 2 → cross out
3: common factor 3 → cross out
4: common factor 4 → cross out
5: only 1 is common → keep
6: common factor 6 → cross out
7: only 1 is common → keep
8: common factor 4 → cross out
9: common factor 3 → cross out
10: common factor 2 → cross out
11: only 1 is common → keep - Write the fractions. These are the ones in simplest form.
,1 12 ,5 12 ,7 12 11 12
Check. Each of 1, 5, 7, 11 has no factor in common with 12 except 1. ✓
Watch out. Do not forget 1/12 and 11/12.
Comparing and ordering fractions
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
Which is bigger,
There are three useful rules.
1. Same denominator: the bigger numerator is the bigger fraction.
To order a list, change every fraction to the same denominator, then order the numerators. Remember to write the original fractions in your answer. You can also compare with
Key ideas
- Same denominator: the bigger numerator is the bigger fraction.
- Same numerator: the smaller denominator is the bigger fraction (halves are bigger than quarters).
- Different denominators: change to a common denominator (a multiple of both), then compare the numerators.
- To order, change every fraction, order the numerators, then write the original fractions.
- Mixed numbers: compare the whole numbers first, or write everything as improper fractions.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=3 4 =3 × 2 4 × 2 6 8 5 8 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.6 > 5
- Write the answer. Use the original fractions in your answer.
>3 4 5 8
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
7 10 =3 5 =3 × 2 5 × 2 6 10 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.7 > 6
- Write the answer. Use the original fractions in your answer.
>7 10 3 5
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 12, so 12 will do.12 ÷ 3 = 4, so 3 goes into 12
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=2 3 =2 × 4 3 × 4 8 12 7 12 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.8 > 7
- Write the answer. Use the original fractions in your answer.
>2 3 7 12
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To order fractions is to put them in a line from the smallest to the largest (ascending) or from the largest to the smallest (descending). Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change every fraction to the same denominator. Then order the numerators.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 2 = 4, so 2 goes into 8
8 ÷ 4 = 2, so 4 goes into 8 - Change every fraction to the common denominator. Multiply the top and the bottom by the same number each time.
=1 2 =1 × 4 2 × 4 4 8 (already in eighths)3 8 =3 4 =3 × 2 4 × 2 6 8 (already in eighths)5 8 - Put the top numbers in order. With the same bottom number, the bigger the top number, the bigger the fraction. We want smallest to largest.3, 4, 5, 6 (out of 8)
- Write the original fractions in that order. The answer uses the fractions from the question, not the changed ones.
,3 8 ,1 2 ,5 8 3 4
Check. Read the numerators again: 3, 4, 5, 6 go up each time. ✓
Watch out. Write down the original fractions in your final answer.
Key words. To order fractions is to put them in a line from the smallest to the largest (ascending) or from the largest to the smallest (descending). Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change every fraction to the same denominator. Then order the numerators.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 12, so 12 will do.12 ÷ 3 = 4, so 3 goes into 12
12 ÷ 6 = 2, so 6 goes into 12 - Change every fraction to the common denominator. Multiply the top and the bottom by the same number each time.
=2 3 =2 × 4 3 × 4 8 12 =5 6 =5 × 2 6 × 2 10 12 (already in twelfths)7 12 - Put the top numbers in order. With the same bottom number, the bigger the top number, the bigger the fraction. We want largest to smallest.10, 8, 7 (out of 12)
- Write the original fractions in that order. The answer uses the fractions from the question, not the changed ones.
,5 6 ,2 3 7 12
Check. Read the numerators again: 10, 8, 7 go down each time. ✓
Watch out. Write down the original fractions in your final answer.
Key words. To order fractions is to put them in a line from the smallest to the largest (ascending) or from the largest to the smallest (descending). Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change every fraction to the same denominator. Then order the numerators.
- Write the mixed numbers as improper fractions. This makes every number a fraction, so we can compare them.1
=3 4 =1 × 4 + 3 4 7 4
2 =2 1
1 =5 8 =1 × 8 + 5 8 13 8 - Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change every fraction to the common denominator. Multiply the top and the bottom by the same number each time.
=7 4 =7 × 2 4 × 2 14 8 =2 1 =2 × 8 1 × 8 16 8 (already in eighths)13 8 (already in eighths)11 8 - Put the top numbers in order. With the same bottom number, the bigger the top number, the bigger the fraction. We want smallest to largest.11, 13, 14, 16 (out of 8)
- Write the original fractions in that order. The answer uses the fractions from the question, not the changed ones.
, 111 8 , 15 8 , 23 4
Check. Read the numerators again: 11, 13, 14, 16 go up each time. ✓
Watch out. Write down the original fractions in your final answer.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Write both fractions with the same denominator. Then pick a numerator between the two numerators.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 4, so 4 will do.4 ÷ 2 = 2, so 2 goes into 4
- Write both fractions with the common denominator. Then we can see the numerators.
=1 2 =1 × 2 2 × 2 2 4 3 4 - There is no whole number between the numerators. Double the denominator. Cutting every part in half makes room.
=2 4 and4 8 =3 4 6 8 - Choose a numerator between them. Any whole number between 4 and 6 works.4 < 5 < 6, so use 5.
- Write the answer.
<1 2 <5 8 3 4
Check.
Watch out. If the numerators are next to each other, double the denominator to make room.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change the fractions to the same denominator (10). Then find the numerators that fit between.
- Write the two end fractions with denominator 10. The box fraction has a bottom number of 10, so we change the others to match.
=3 5 =3 × 2 5 × 2 6 10 =4 5 =4 × 2 5 × 2 8 10 - Look at the numerators. The box must be bigger than the first numerator and smaller than the second.6 < ? < 8
- List the numbers that fit. Only whole numbers go in the box.7
Check. Try it:
Watch out. The numbers at the ends do not count: the box has to be strictly between them.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. To compare fractions that have different denominators, change them to the same denominator. Then compare the numerators.
- Find a common denominator. We need a number that all the denominators go into. List the multiples of each one until you see a number in every list.Multiples of 5: 5, 10, 15, 20, 25, 30, 35, 40
Multiples of 8: 8, 16, 24, 32, 40
The first number in every list is 40. - Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time.
=3 5 =3 × 8 5 × 8 24 40 =5 8 =5 × 5 8 × 5 25 40 - Compare the top numbers. With the same denominator, the bigger numerator is the bigger fraction.24 < 25, so
<24 40 25 40 - Write a sentence to prove it. In a “prove it” question the last line must say what you have shown.No.
=3 5 and24 40 =5 8 , and 24 is less than 25. So25 40 is less than3 5 .5 8
Check. The bars: the
Watch out. Do not guess from the numbers. Show the common denominator and the two new fractions.
Watch out
A bigger denominator does not make a bigger fraction.Exercise 6C Comparing and ordering fractions
Non-calculatorKey words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. The denominators are the same, so compare the numerators.
- Look at the denominators. If the bottom numbers are the same, the parts are the same size.Both are 8, so we can compare the top numbers.
- Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.3 < 5
- Write the answer. Use the original fractions in your answer.
<3 8 5 8
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. The denominators are the same, so compare the numerators.
- Look at the denominators. If the bottom numbers are the same, the parts are the same size.Both are 10, so we can compare the top numbers.
- Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.7 > 4
- Write the answer. Use the original fractions in your answer.
>7 10 4 10
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. The denominators are the same, so compare the numerators.
- Look at the denominators. If the bottom numbers are the same, the parts are the same size.Both are 12, so we can compare the top numbers.
- Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.5 < 9
- Write the answer. Use the original fractions in your answer.
<5 12 9 12
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. The denominators are the same, so compare the numerators.
- Look at the denominators. If the bottom numbers are the same, the parts are the same size.Both are 7, so we can compare the top numbers.
- Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.6 > 2
- Write the answer. Use the original fractions in your answer.
>6 7 2 7
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. We need a number that all the denominators go into. List the multiples of each one until you see a number in every list.Multiples of 3: 3, 6, 9, 12, 15
Multiples of 5: 5, 10, 15
The first number in every list is 15. - Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=1 3 =1 × 5 3 × 5 5 15 =1 5 =1 × 3 5 × 3 3 15 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.5 > 3
- Write the answer. Use the original fractions in your answer.
>1 3 1 5
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=3 4 =3 × 2 4 × 2 6 8 3 8 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.6 > 3
- Write the answer. Use the original fractions in your answer.
>3 4 3 8
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. We need a number that all the denominators go into. List the multiples of each one until you see a number in every list.Multiples of 3: 3, 6, 9, 12, 15
Multiples of 5: 5, 10, 15
The first number in every list is 15. - Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=2 5 =2 × 3 5 × 3 6 15 =2 3 =2 × 5 3 × 5 10 15 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.6 < 10
- Write the answer. Use the original fractions in your answer.
<2 5 2 3
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 12, so 12 will do.12 ÷ 6 = 2, so 6 goes into 12
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=5 6 =5 × 2 6 × 2 10 12 5 12 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.10 > 5
- Write the answer. Use the original fractions in your answer.
>5 6 5 12
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 2 = 4, so 2 goes into 8
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=1 2 =1 × 4 2 × 4 4 8 3 8 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.4 > 3
- Write the answer. Use the original fractions in your answer.
>1 2 3 8
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=3 4 =3 × 2 4 × 2 6 8 5 8 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.6 > 5
- Write the answer. Use the original fractions in your answer.
>3 4 5 8
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=1 4 =1 × 2 4 × 2 2 8 3 8 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.2 < 3
- Write the answer. Use the original fractions in your answer.
<1 4 3 8
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
7 8 =3 4 =3 × 2 4 × 2 6 8 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.7 > 6
- Write the answer. Use the original fractions in your answer.
>7 8 3 4
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 6, so 6 will do.6 ÷ 3 = 2, so 3 goes into 6
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=2 3 =2 × 2 3 × 2 4 6 5 6 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.4 < 5
- Write the answer. Use the original fractions in your answer.
<2 3 5 6
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=3 4 =3 × 2 4 × 2 6 8 5 8 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.6 > 5
- Write the answer. Use the original fractions in your answer.
>3 4 5 8
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
7 10 =3 5 =3 × 2 5 × 2 6 10 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.7 > 6
- Write the answer. Use the original fractions in your answer.
>7 10 3 5
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 12, so 12 will do.12 ÷ 3 = 4, so 3 goes into 12
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
5 12 =1 3 =1 × 4 3 × 4 4 12 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.5 > 4
- Write the answer. Use the original fractions in your answer.
>5 12 1 3
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=4 5 =4 × 2 5 × 2 8 10 7 10 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.8 > 7
- Write the answer. Use the original fractions in your answer.
>4 5 7 10
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 12, so 12 will do.12 ÷ 2 = 6, so 2 goes into 12
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=1 2 =1 × 6 2 × 6 6 12 5 12 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.6 > 5
- Write the answer. Use the original fractions in your answer.
>1 2 5 12
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
5 8 =3 4 =3 × 2 4 × 2 6 8 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.5 < 6
- Write the answer. Use the original fractions in your answer.
<5 8 , so the bigger one is3 4 .3 4
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
3 10 =1 5 =1 × 2 5 × 2 2 10 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.3 > 2
- Write the answer. Use the original fractions in your answer.
>3 10 , so the bigger one is1 5 .3 10
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To order fractions is to put them in a line from the smallest to the largest (ascending) or from the largest to the smallest (descending). Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change every fraction to the same denominator. Then order the numerators.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 2 = 5, so 2 goes into 10
10 ÷ 5 = 2, so 5 goes into 10 - Change every fraction to the common denominator. Multiply the top and the bottom by the same number each time.
(already in tenths)3 10 =1 2 =1 × 5 2 × 5 5 10 =2 5 =2 × 2 5 × 2 4 10 - Put the top numbers in order. With the same bottom number, the bigger the top number, the bigger the fraction. We want smallest to largest.3, 4, 5 (out of 10)
- Write the original fractions in that order. The answer uses the fractions from the question, not the changed ones.
,3 10 ,2 5 1 2
Check. Read the numerators again: 3, 4, 5 go up each time. ✓
Watch out. Write down the original fractions in your final answer.
Key words. To order fractions is to put them in a line from the smallest to the largest (ascending) or from the largest to the smallest (descending). Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change every fraction to the same denominator. Then order the numerators.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 16, so 16 will do.16 ÷ 2 = 8, so 2 goes into 16
16 ÷ 4 = 4, so 4 goes into 16
16 ÷ 8 = 2, so 8 goes into 16 - Change every fraction to the common denominator. Multiply the top and the bottom by the same number each time.
=3 4 =3 × 4 4 × 4 12 16 =5 8 =5 × 2 8 × 2 10 16 =1 2 =1 × 8 2 × 8 8 16 (already in sixteenths)11 16 - Put the top numbers in order. With the same bottom number, the bigger the top number, the bigger the fraction. We want smallest to largest.8, 10, 11, 12 (out of 16)
- Write the original fractions in that order. The answer uses the fractions from the question, not the changed ones.
,1 2 ,5 8 ,11 16 3 4
Check. Read the numerators again: 8, 10, 11, 12 go up each time. ✓
Watch out. Write down the original fractions in your final answer.
Key words. To order fractions is to put them in a line from the smallest to the largest (ascending) or from the largest to the smallest (descending). Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change every fraction to the same denominator. Then order the numerators.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 12, so 12 will do.12 ÷ 2 = 6, so 2 goes into 12
12 ÷ 3 = 4, so 3 goes into 12
12 ÷ 6 = 2, so 6 goes into 12 - Change every fraction to the common denominator. Multiply the top and the bottom by the same number each time.
(already in twelfths)7 12 =2 3 =2 × 4 3 × 4 8 12 =1 2 =1 × 6 2 × 6 6 12 =5 6 =5 × 2 6 × 2 10 12 - Put the top numbers in order. With the same bottom number, the bigger the top number, the bigger the fraction. We want smallest to largest.6, 7, 8, 10 (out of 12)
- Write the original fractions in that order. The answer uses the fractions from the question, not the changed ones.
,1 2 ,7 12 ,2 3 5 6
Check. Read the numerators again: 6, 7, 8, 10 go up each time. ✓
Watch out. Write down the original fractions in your final answer.
Key words. To order fractions is to put them in a line from the smallest to the largest (ascending) or from the largest to the smallest (descending). Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change every fraction to the same denominator. Then order the numerators.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change every fraction to the common denominator. Multiply the top and the bottom by the same number each time.
=4 5 =4 × 2 5 × 2 8 10 (already in tenths)7 10 =3 5 =3 × 2 5 × 2 6 10 (already in tenths)9 10 - Put the top numbers in order. With the same bottom number, the bigger the top number, the bigger the fraction. We want smallest to largest.6, 7, 8, 9 (out of 10)
- Write the original fractions in that order. The answer uses the fractions from the question, not the changed ones.
,3 5 ,7 10 ,4 5 9 10
Check. Read the numerators again: 6, 7, 8, 9 go up each time. ✓
Watch out. Write down the original fractions in your final answer.
Key words. To order fractions is to put them in a line from the smallest to the largest (ascending) or from the largest to the smallest (descending). Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change every fraction to the same denominator. Then order the numerators.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 12, so 12 will do.12 ÷ 3 = 4, so 3 goes into 12
12 ÷ 4 = 3, so 4 goes into 12
12 ÷ 6 = 2, so 6 goes into 12 - Change every fraction to the common denominator. Multiply the top and the bottom by the same number each time.
=5 6 =5 × 2 6 × 2 10 12 =2 3 =2 × 4 3 × 4 8 12 =3 4 =3 × 3 4 × 3 9 12 (already in twelfths)7 12 - Put the top numbers in order. With the same bottom number, the bigger the top number, the bigger the fraction. We want largest to smallest.10, 9, 8, 7 (out of 12)
- Write the original fractions in that order. The answer uses the fractions from the question, not the changed ones.
,5 6 ,3 4 ,2 3 7 12
Check. Read the numerators again: 10, 9, 8, 7 go down each time. ✓
Watch out. Write down the original fractions in your final answer.
Key words. To order fractions is to put them in a line from the smallest to the largest (ascending) or from the largest to the smallest (descending). Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change every fraction to the same denominator. Then order the numerators.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 2 = 4, so 2 goes into 8
8 ÷ 4 = 2, so 4 goes into 8 - Change every fraction to the common denominator. Multiply the top and the bottom by the same number each time.
(already in eighths)3 8 =1 2 =1 × 4 2 × 4 4 8 =1 4 =1 × 2 4 × 2 2 8 - Put the top numbers in order. With the same bottom number, the bigger the top number, the bigger the fraction. We want largest to smallest.4, 3, 2 (out of 8)
- Write the original fractions in that order. The answer uses the fractions from the question, not the changed ones.
,1 2 ,3 8 1 4
Check. Read the numerators again: 4, 3, 2 go down each time. ✓
Watch out. Write down the original fractions in your final answer.
Key words. The denominator (bottom number) tells us how many equal parts the whole is cut into. The numerator (top number) tells us how many parts we have.
Method. Count the steps from 0 to each letter. Each step is one twelfth.
- Count to A. A is 3 steps from 0.
3 12 - Count to B. B is 8 steps from 0.
8 12 - Count to C. C is 5 steps from 0.
5 12
Check. The denominator is 12 for all of them. ✓
Watch out. Count the steps (gaps), not the tick marks.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Read each letter in twelfths, then compare the numerators.
- Write A, B and C as twelfths. Each step on the line is one twelfth.A =
, B =3 12 , C =8 12 5 12 - Compare the numerators. All three have the same denominator.8 > 5 > 3
- Write the order. B has the biggest numerator.B is the largest, then C, then A.
Check. B is furthest to the right on the line. ✓
Watch out. Count the steps from 0.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change the fractions to the same denominator (10). Then find the numerators that fit between.
- Write the two end fractions with denominator 10. The box fraction has a bottom number of 10, so we change the others to match.
=3 5 =3 × 2 5 × 2 6 10 =4 5 =4 × 2 5 × 2 8 10 - Look at the numerators. The box must be bigger than the first numerator and smaller than the second.6 < ? < 8
- List the numbers that fit. Only whole numbers go in the box.7
Check. Try it:
Watch out. The numbers at the ends do not count: the box has to be strictly between them.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change the fractions to the same denominator (8). Then find the numerators that fit between.
- Write the two end fractions with denominator 8. The box fraction has a bottom number of 8, so we change the others to match.
=1 2 =1 × 4 2 × 4 4 8 =3 4 =3 × 2 4 × 2 6 8 - Look at the numerators. The box must be bigger than the first numerator and smaller than the second.4 < ? < 6
- List the numbers that fit. Only whole numbers go in the box.5
Check. Try it:
Watch out. The numbers at the ends do not count: the box has to be strictly between them.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change the fractions to the same denominator (12). Then find the numerators that fit between.
- Write the two end fractions with denominator 12. The box fraction has a bottom number of 12, so we change the others to match.
=1 3 =1 × 4 3 × 4 4 12 =1 2 =1 × 6 2 × 6 6 12 - Look at the numerators. The box must be bigger than the first numerator and smaller than the second.4 < ? < 6
- List the numbers that fit. Only whole numbers go in the box.5
Check. Try it:
Watch out. The numbers at the ends do not count: the box has to be strictly between them.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change the fractions to the same denominator (20). Then find the numerators that fit between.
- Write the two end fractions with denominator 20. The box fraction has a bottom number of 20, so we change the others to match.
=2 5 =2 × 4 5 × 4 8 20 =1 2 =1 × 10 2 × 10 10 20 - Look at the numerators. The box must be bigger than the first numerator and smaller than the second.8 < ? < 10
- List the numbers that fit. Only whole numbers go in the box.9
Check. Try it:
Watch out. The numbers at the ends do not count: the box has to be strictly between them.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. A fraction is greater than
- Find half of each denominator. Half of a whole is the same as half the number of parts.
: half of 8 is 4, and 3 is less than 4 → less than3 8 1 2 : half of 8 is 4, and 5 is more than 4 → greater than5 8 1 2 : half of 10 is 5, and 4 is less than 5 → less than4 10 1 2 : half of 12 is 6, and 7 is more than 6 → greater than7 12 1 2 : half of 12 is 6, and 6 is equal to 6 → equal to6 12 1 2 - Pick the fractions that are greater than one half. Ignore any that are equal or smaller.
,5 8 7 12
Check.
Watch out. A fraction equal to one half, like 6/12, is not greater than one half.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Write the mixed numbers as improper fractions. This makes every number a fraction, so we can compare them.1
=3 4 =1 × 4 + 3 4 7 4
1 =5 8 =1 × 8 + 5 8 13 8 - Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=7 4 =7 × 2 4 × 2 14 8 13 8 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.14 > 13
- Write the answer. Use the original fractions in your answer.1
> 13 4 5 8
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Write the mixed numbers as improper fractions. This makes every number a fraction, so we can compare them.2
=1 2 =2 × 2 + 1 2 5 2
2 =4 10 =2 × 10 + 4 10 24 10 - Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 2 = 5, so 2 goes into 10
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
=5 2 =5 × 5 2 × 5 25 10 24 10 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.25 > 24
- Write the answer. Use the original fractions in your answer.2
> 21 2 4 10
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Write the mixed numbers as improper fractions. This makes every number a fraction, so we can compare them.2
=1 2 =2 × 2 + 1 2 5 2 - Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 4, so 4 will do.4 ÷ 2 = 2, so 2 goes into 4
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
9 4 =5 2 =5 × 2 2 × 2 10 4 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.9 < 10
- Write the answer. Use the original fractions in your answer.
< 29 4 1 2
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Write the mixed numbers as improper fractions. This makes every number a fraction, so we can compare them.1
=7 8 =1 × 8 + 7 8 15 8
2 =2 1 - Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
15 8 =2 1 =2 × 8 1 × 8 16 8 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.15 < 16
- Write the answer. Use the original fractions in your answer.1
< 27 8
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To order fractions is to put them in a line from the smallest to the largest (ascending) or from the largest to the smallest (descending). Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change every fraction to the same denominator. Then order the numerators.
- Write the mixed numbers as improper fractions. This makes every number a fraction, so we can compare them.1
=1 2 =1 × 2 + 1 2 3 2
1 =7 8 =1 × 8 + 7 8 15 8 - Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 2 = 4, so 2 goes into 8
8 ÷ 4 = 2, so 4 goes into 8 - Change every fraction to the common denominator. Multiply the top and the bottom by the same number each time.
=3 2 =3 × 4 2 × 4 12 8 =5 4 =5 × 2 4 × 2 10 8 (already in eighths)15 8 (already in eighths)11 8 - Put the top numbers in order. With the same bottom number, the bigger the top number, the bigger the fraction. We want smallest to largest.10, 11, 12, 15 (out of 8)
- Write the original fractions in that order. The answer uses the fractions from the question, not the changed ones.
,5 4 , 111 8 , 11 2 7 8
Check. Read the numerators again: 10, 11, 12, 15 go up each time. ✓
Watch out. Write down the original fractions in your final answer.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. To compare fractions that have different denominators, change them to the same denominator. Then compare the numerators.
- Find a common denominator. We need a number that all the denominators go into. List the multiples of each one until you see a number in every list.Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24
Multiples of 8: 8, 16, 24
The first number in every list is 24. - Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time.
=5 8 =5 × 3 8 × 3 15 24 =2 3 =2 × 8 3 × 8 16 24 - Compare the top numbers. With the same denominator, the bigger numerator is the bigger fraction.15 < 16, so
<15 24 16 24 - Write a sentence to prove it. In a “prove it” question the last line must say what you have shown.No.
=5 8 and15 24 =2 3 , and 15 is less than 16. So16 24 is less than5 8 .2 3
Check. The bars: the
Watch out. Do not guess from the numbers. Show the common denominator and the two new fractions.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Work the question out yourself first. Then compare your working with the working in the question and find where it goes wrong.
- Work it out correctly. We need the right answer to compare with.
=1 4 and3 12 =1 6 . 3 > 2, so2 12 >1 4 .1 6 - Find the mistake. Leo compared the bottom numbers. A bigger bottom number means the whole is cut into more, smaller pieces. So each piece is smaller.Leo says
>1 6 because 6 is bigger than 4.1 4 - Write the correct answer. The correct answer is
<1 6 .1 4
Check. On a fraction wall the sixth brick is shorter than the quarter brick. ✓
Watch out. Think about sharing a pizza: more people means smaller slices.
Key words. Always means true every time. Never means false every time. Sometimes means true for some numbers and false for others.
Method. Test the statement with some numbers. If it is always true, never true, or true for some numbers only, that gives the answer.
- Try some examples. Testing numbers helps us see if the statement is true every time.
<3 8 (3 < 5)5 8 <2 9 (2 < 7)7 9 >4 5 (4 > 1)1 5 - Decide: always, sometimes or never? When the denominators are the same, the parts are the same size. So more parts means a bigger fraction.Always
Check. Every example agreed. ✓
Watch out. To show a statement is “always” true you need a reason. A few examples are not enough to prove it, but one counter-example shows it is not always true.
Key words. Always means true every time. Never means false every time. Sometimes means true for some numbers and false for others.
Method. Test the statement with some numbers. If it is always true, never true, or true for some numbers only, that gives the answer.
- Try some examples. Testing numbers helps us see if the statement is true every time.
and1 3 : the bigger denominator (5) gives the smaller fraction, since1 5 <1 5 .1 3 - Look for an example that does not work. One example that breaks the rule is a counter-example.
and1 4 : the bigger denominator (8) gives the bigger fraction, since3 8 =1 4 <2 8 .3 8 - Decide: always, sometimes or never? It works when the numerators are the same, but not always when the numerators are different.Sometimes
Check. We found one example that works and one that does not. ✓
Watch out. To show a statement is “always” true you need a reason. A few examples are not enough to prove it, but one counter-example shows it is not always true.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Write both fractions with the same denominator. Then pick a numerator between the two numerators.
- Find a common denominator. We need a number that all the denominators go into. List the multiples of each one until you see a number in every list.Multiples of 2: 2, 4, 6, 8, 10
Multiples of 5: 5, 10
The first number in every list is 10. - Write both fractions with the common denominator. Then we can see the numerators.
=2 5 =2 × 2 5 × 2 4 10 =1 2 =1 × 5 2 × 5 5 10 - There is no whole number between the numerators. Double the denominator. Cutting every part in half makes room.
=4 10 and8 20 =5 10 10 20 - Choose a numerator between them. Any whole number between 8 and 10 works.8 < 9 < 10, so use 9.
- Write the answer.
<2 5 <9 20 1 2
Check.
Watch out. If the numerators are next to each other, double the denominator to make room.
Improper fractions and mixed numbers
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
When the top number is bigger than (or equal to) the bottom number, we have an improper fraction. It is worth 1 whole or more. The picture shows
Improper to mixed: divide the top by the bottom. The answer is the whole number and the remainder is the new top number.
A fraction is a division. The line in a fraction means divide. If 3 cakes are shared equally between 4 people, each person gets 3 ÷ 4 =
Key ideas
- An improper fraction has a top number that is bigger than or equal to the bottom number:
.11 4 - A mixed number is a whole number and a fraction: 2
.3 4 - Improper → mixed: divide the top by the bottom. Whole number = answer, new top = remainder.
- Mixed → improper: whole × bottom + top, over the same bottom number.
- The fraction line means divide: 3 ÷ 4 =
.3 4
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count the equal parts in one whole for the bottom number. Count all the shaded parts for the top number. The full whole ones give the mixed number.
- Look at how each bar is cut. Every bar is cut into the same number of equal parts. That number is the denominator.Each bar has 4 equal parts, so the denominator is 4.
- Count all the shaded parts. The total number of shaded parts is the numerator.2 full bars of 4 parts and 3 more parts: 2 × 4 + 3 = 11
- Write the improper fraction and the mixed number. There are 2 whole bars shaded and
of another.3 4 = 211 4 3 4
Check. 2 × 4 + 3 = 11. ✓
Watch out. Count every shaded part in all the shapes, not just the last one.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. An improper fraction has more parts than one whole. Divide the top by the bottom to find how many whole ones it holds.
- Divide 17 by 5. The fraction line means divide. The answer tells us how many whole ones we can make.17 ÷ 5 = 3 remainder 2
- The whole number is 3. 3 lots of 5 fifths make 3 whole ones: 3 × 5 = 15.17 − 15 = 2 fifths are left over.
- Write the leftover parts as a fraction. The remainder is the numerator. The denominator stays 5.3 and
= 32 5 2 5
Check. Change back: 3 × 5 + 2 = 17 = 17. ✓
Watch out. The leftover (remainder) goes on top of the same denominator. Do not put it over the whole number.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. An improper fraction has more parts than one whole. Divide the top by the bottom to find how many whole ones it holds.
- Divide 22 by 8. The fraction line means divide. The answer tells us how many whole ones we can make.22 ÷ 8 = 2 remainder 6
- The whole number is 2. 2 lots of 8 eighths make 2 whole ones: 2 × 8 = 16.22 − 16 = 6 eighths are left over.
- Write the leftover parts as a fraction. The remainder is the numerator. The denominator stays 8.2 and
= 26 8 6 8 - Simplify the fraction part. 6 and 8 can both be divided by 2.
=6 8 , so 23 4 = 26 8 3 4
Check. Change back: 2 × 8 + 6 = 22 = 22. ✓
Watch out. The leftover (remainder) goes on top of the same denominator. Do not put it over the whole number.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count how many parts there are altogether. A whole number is worth the denominator in parts.
- Change the 3 wholes into fifths. One whole is
, so 3 wholes are 3 lots of 5.5 5 3 × 5 = 15, so 3 =15 5 - Add the 2 extra fifths. The fraction part is already in the same size parts.15 + 2 = 17
- Write the improper fraction. The denominator stays the same.3
=2 5 17 5
Check. Change back: 17 ÷ 5 = 3 remainder 2, so
Watch out. Multiply the whole number by the denominator, then add the numerator. Do not just write the digits next to each other.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count the equal steps from the nearest whole number (or from 0).
- Find the whole numbers either side. The point is between two whole numbers.It is between 2 and 3.
- Count the small steps. Each step is
. There are 4 equal steps between each pair of whole numbers.1 4 From 2 it is 3 steps along, so it is 3 quarters more than 2. - Write it as a mixed number and as an improper fraction. 2 wholes are 8 quarters. Add 3 more.2
=3 4 11 4
Check. 2 × 4 + 3 = 11. ✓
Watch out. Count the steps between the numbers, not the tick marks. There is one more tick mark than there are steps.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 5, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+2 5 =4 5 =2 + 4 5 6 5 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 6 ÷ 5.6 5 = 16 5 1 5 - Write the answer.
+2 5 = 14 5 1 5
Check. Take away: 1
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. The line in a fraction means divide. So
Method. The fraction line means divide. So a ÷ b is the fraction a over b. If the top is bigger, change it to a mixed number.
- Write the division as a fraction. A fraction line means divide, so the top number is the number being shared.7 ÷ 4 =
7 4 - Change it to a mixed number. 7 wholes shared between 4: each gets 1 whole, and 3 wholes are left to share.7 ÷ 4 = 1 remainder 3
- Write the left-over part as a fraction. The 3 left over are shared between 4, so each gets
.3 4 1 and = 13 4 3 4 - Write the answer. 1
3 4
Check. Multiply back: 1
Watch out. Put the number you are dividing (the one being shared) on the top.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. The denominators are the same, so compare the numerators.
- Write the mixed numbers as improper fractions. This makes every number a fraction, so we can compare them.3
=1 5 =3 × 5 + 1 5 16 5 - Look at the denominators. If the bottom numbers are the same, the parts are the same size.Both are 5, so we can compare the top numbers.
- Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.17 > 16
- Write the answer. Use the original fractions in your answer.
> 317 5 1 5
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Watch out
Write the remainder over the old bottom number: 17 ÷ 5 = 3 remainder 2 gives 3Exercise 6D Improper fractions and mixed numbers
Non-calculatorKey words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count the equal parts in one whole for the bottom number. Count all the shaded parts for the top number. The full whole ones give the mixed number.
- Look at how each bar is cut. Every bar is cut into the same number of equal parts. That number is the denominator.Each bar has 4 equal parts, so the denominator is 4.
- Count all the shaded parts. The total number of shaded parts is the numerator.1 full bars of 4 parts and 3 more parts: 1 × 4 + 3 = 7
- Write the improper fraction and the mixed number. There are 1 whole bars shaded and
of another.3 4 = 17 4 3 4
Check. 1 × 4 + 3 = 7. ✓
Watch out. Count every shaded part in all the shapes, not just the last one.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count the equal parts in one whole for the bottom number. Count all the shaded parts for the top number. The full whole ones give the mixed number.
- Look at how each circle is cut. Every circle is cut into the same number of equal parts. That number is the denominator.Each circle has 5 equal parts, so the denominator is 5.
- Count all the shaded parts. The total number of shaded parts is the numerator.1 full circles of 5 parts and 4 more parts: 1 × 5 + 4 = 9
- Write the improper fraction and the mixed number. There are 1 whole circles shaded and
of another.4 5 = 19 5 4 5
Check. 1 × 5 + 4 = 9. ✓
Watch out. Count every shaded part in all the shapes, not just the last one.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count the equal parts in one whole for the bottom number. Count all the shaded parts for the top number. The full whole ones give the mixed number.
- Look at how each bar is cut. Every bar is cut into the same number of equal parts. That number is the denominator.Each bar has 3 equal parts, so the denominator is 3.
- Count all the shaded parts. The total number of shaded parts is the numerator.3 full bars of 3 parts and 2 more parts: 3 × 3 + 2 = 11
- Write the improper fraction and the mixed number. There are 3 whole bars shaded and
of another.2 3 = 311 3 2 3
Check. 3 × 3 + 2 = 11. ✓
Watch out. Count every shaded part in all the shapes, not just the last one.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. An improper fraction has more parts than one whole. Divide the top by the bottom to find how many whole ones it holds.
- Divide 7 by 4. The fraction line means divide. The answer tells us how many whole ones we can make.7 ÷ 4 = 1 remainder 3
- The whole number is 1. 1 lots of 4 quarters make 1 whole ones: 1 × 4 = 4.7 − 4 = 3 quarters are left over.
- Write the leftover parts as a fraction. The remainder is the numerator. The denominator stays 4.1 and
= 13 4 3 4
Check. Change back: 1 × 4 + 3 = 7 = 7. ✓
Watch out. The leftover (remainder) goes on top of the same denominator. Do not put it over the whole number.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. An improper fraction has more parts than one whole. Divide the top by the bottom to find how many whole ones it holds.
- Divide 9 by 5. The fraction line means divide. The answer tells us how many whole ones we can make.9 ÷ 5 = 1 remainder 4
- The whole number is 1. 1 lots of 5 fifths make 1 whole ones: 1 × 5 = 5.9 − 5 = 4 fifths are left over.
- Write the leftover parts as a fraction. The remainder is the numerator. The denominator stays 5.1 and
= 14 5 4 5
Check. Change back: 1 × 5 + 4 = 9 = 9. ✓
Watch out. The leftover (remainder) goes on top of the same denominator. Do not put it over the whole number.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. An improper fraction has more parts than one whole. Divide the top by the bottom to find how many whole ones it holds.
- Divide 13 by 3. The fraction line means divide. The answer tells us how many whole ones we can make.13 ÷ 3 = 4 remainder 1
- The whole number is 4. 4 lots of 3 thirds make 4 whole ones: 4 × 3 = 12.13 − 12 = 1 thirds are left over.
- Write the leftover parts as a fraction. The remainder is the numerator. The denominator stays 3.4 and
= 41 3 1 3
Check. Change back: 4 × 3 + 1 = 13 = 13. ✓
Watch out. The leftover (remainder) goes on top of the same denominator. Do not put it over the whole number.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. An improper fraction has more parts than one whole. Divide the top by the bottom to find how many whole ones it holds.
- Divide 17 by 6. The fraction line means divide. The answer tells us how many whole ones we can make.17 ÷ 6 = 2 remainder 5
- The whole number is 2. 2 lots of 6 sixths make 2 whole ones: 2 × 6 = 12.17 − 12 = 5 sixths are left over.
- Write the leftover parts as a fraction. The remainder is the numerator. The denominator stays 6.2 and
= 25 6 5 6
Check. Change back: 2 × 6 + 5 = 17 = 17. ✓
Watch out. The leftover (remainder) goes on top of the same denominator. Do not put it over the whole number.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. An improper fraction has more parts than one whole. Divide the top by the bottom to find how many whole ones it holds.
- Divide 22 by 8. The fraction line means divide. The answer tells us how many whole ones we can make.22 ÷ 8 = 2 remainder 6
- The whole number is 2. 2 lots of 8 eighths make 2 whole ones: 2 × 8 = 16.22 − 16 = 6 eighths are left over.
- Write the leftover parts as a fraction. The remainder is the numerator. The denominator stays 8.2 and
= 26 8 6 8 - Simplify the fraction part. 6 and 8 can both be divided by 2.
=6 8 , so 23 4 = 26 8 3 4
Check. Change back: 2 × 8 + 6 = 22 = 22. ✓
Watch out. The leftover (remainder) goes on top of the same denominator. Do not put it over the whole number.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. An improper fraction has more parts than one whole. Divide the top by the bottom to find how many whole ones it holds.
- Divide 12 by 4. The fraction line means divide. The answer tells us how many whole ones we can make.12 ÷ 4 = 3 remainder 0
- The whole number is 3. 3 lots of 4 quarters make 3 whole ones: 3 × 4 = 12.Nothing is left over.
- Write the answer. It is a whole number.3
Check. Change back: 3 × 4 + 0 = 12 = 12. ✓
Watch out. The leftover (remainder) goes on top of the same denominator. Do not put it over the whole number.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count how many parts there are altogether. A whole number is worth the denominator in parts.
- Change the 1 whole into thirds. One whole is
, so 1 wholes are 1 lots of 3.3 3 1 × 3 = 3, so 1 =3 3 - Add the 2 extra thirds. The fraction part is already in the same size parts.3 + 2 = 5
- Write the improper fraction. The denominator stays the same.1
=2 3 5 3
Check. Change back: 5 ÷ 3 = 1 remainder 2, so
Watch out. Multiply the whole number by the denominator, then add the numerator. Do not just write the digits next to each other.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count how many parts there are altogether. A whole number is worth the denominator in parts.
- Change the 2 wholes into quarters. One whole is
, so 2 wholes are 2 lots of 4.4 4 2 × 4 = 8, so 2 =8 4 - Add the 3 extra quarters. The fraction part is already in the same size parts.8 + 3 = 11
- Write the improper fraction. The denominator stays the same.2
=3 4 11 4
Check. Change back: 11 ÷ 4 = 2 remainder 3, so
Watch out. Multiply the whole number by the denominator, then add the numerator. Do not just write the digits next to each other.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count how many parts there are altogether. A whole number is worth the denominator in parts.
- Change the 3 wholes into fifths. One whole is
, so 3 wholes are 3 lots of 5.5 5 3 × 5 = 15, so 3 =15 5 - Add the 1 extra fifths. The fraction part is already in the same size parts.15 + 1 = 16
- Write the improper fraction. The denominator stays the same.3
=1 5 16 5
Check. Change back: 16 ÷ 5 = 3 remainder 1, so
Watch out. Multiply the whole number by the denominator, then add the numerator. Do not just write the digits next to each other.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count how many parts there are altogether. A whole number is worth the denominator in parts.
- Change the 4 wholes into eighths. One whole is
, so 4 wholes are 4 lots of 8.8 8 4 × 8 = 32, so 4 =32 8 - Add the 5 extra eighths. The fraction part is already in the same size parts.32 + 5 = 37
- Write the improper fraction. The denominator stays the same.4
=5 8 37 8
Check. Change back: 37 ÷ 8 = 4 remainder 5, so
Watch out. Multiply the whole number by the denominator, then add the numerator. Do not just write the digits next to each other.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count how many parts there are altogether. A whole number is worth the denominator in parts.
- Change the 2 wholes into tenths. One whole is
, so 2 wholes are 2 lots of 10.10 10 2 × 10 = 20, so 2 =20 10 - Add the 7 extra tenths. The fraction part is already in the same size parts.20 + 7 = 27
- Write the improper fraction. The denominator stays the same.2
=7 10 27 10
Check. Change back: 27 ÷ 10 = 2 remainder 7, so
Watch out. Multiply the whole number by the denominator, then add the numerator. Do not just write the digits next to each other.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count how many parts there are altogether. A whole number is worth the denominator in parts.
- Change the 5 wholes into halves. One whole is
, so 5 wholes are 5 lots of 2.2 2 5 × 2 = 10, so 5 =10 2 - Add the 1 extra halves. The fraction part is already in the same size parts.10 + 1 = 11
- Write the improper fraction. The denominator stays the same.5
=1 2 11 2
Check. Change back: 11 ÷ 2 = 5 remainder 1, so
Watch out. Multiply the whole number by the denominator, then add the numerator. Do not just write the digits next to each other.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count the equal steps from the nearest whole number (or from 0).
- Find the whole numbers either side. The point is between two whole numbers.It is between 1 and 2.
- Count the small steps. Each step is
. There are 4 equal steps between each pair of whole numbers.1 4 From 1 it is 1 step along, so it is 1 quarter more than 1. - Write it as a mixed number and as an improper fraction. 1 wholes are 4 quarters. Add 1 more.1
=1 4 5 4
Check. 1 × 4 + 1 = 5. ✓
Watch out. Count the steps between the numbers, not the tick marks. There is one more tick mark than there are steps.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count the equal steps from the nearest whole number (or from 0).
- Find the whole numbers either side. The point is between two whole numbers.It is between 2 and 3.
- Count the small steps. Each step is
. There are 4 equal steps between each pair of whole numbers.1 4 From 2 it is 1 step along, so it is 1 quarter more than 2. - Write it as a mixed number and as an improper fraction. 2 wholes are 8 quarters. Add 1 more.2
=1 4 9 4
Check. 2 × 4 + 1 = 9. ✓
Watch out. Count the steps between the numbers, not the tick marks. There is one more tick mark than there are steps.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count the equal steps from the nearest whole number (or from 0).
- Find the whole numbers either side. The point is between two whole numbers.It is between 2 and 3.
- Count the small steps. Each step is
. There are 4 equal steps between each pair of whole numbers.1 4 From 2 it is 3 steps along, so it is 3 quarters more than 2. - Write it as a mixed number and as an improper fraction. 2 wholes are 8 quarters. Add 3 more.2
=3 4 11 4
Check. 2 × 4 + 3 = 11. ✓
Watch out. Count the steps between the numbers, not the tick marks. There is one more tick mark than there are steps.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count the equal steps from the nearest whole number (or from 0).
- Find the whole numbers either side. The point is between two whole numbers.It is between 1 and 2.
- Count the small steps. Each step is
. There are 5 equal steps between each pair of whole numbers.1 5 From 1 it is 2 steps along, so it is 2 fifths more than 1. - Write it as a mixed number and as an improper fraction. 1 wholes are 5 fifths. Add 2 more.1
=2 5 7 5
Check. 1 × 5 + 2 = 7. ✓
Watch out. Count the steps between the numbers, not the tick marks. There is one more tick mark than there are steps.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count the equal steps from the nearest whole number (or from 0).
- Find the whole numbers either side. The point is between two whole numbers.It is between 2 and 3.
- Count the small steps. Each step is
. There are 5 equal steps between each pair of whole numbers.1 5 From 2 it is 1 step along, so it is 1 fifth more than 2. - Write it as a mixed number and as an improper fraction. 2 wholes are 10 fifths. Add 1 more.2
=1 5 11 5
Check. 2 × 5 + 1 = 11. ✓
Watch out. Count the steps between the numbers, not the tick marks. There is one more tick mark than there are steps.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count the equal steps from the nearest whole number (or from 0).
- Find the whole numbers either side. The point is between two whole numbers.It is between 2 and 3.
- Count the small steps. Each step is
. There are 5 equal steps between each pair of whole numbers.1 5 From 2 it is 4 steps along, so it is 4 fifths more than 2. - Write it as a mixed number and as an improper fraction. 2 wholes are 10 fifths. Add 4 more.2
=4 5 14 5
Check. 2 × 5 + 4 = 14. ✓
Watch out. Count the steps between the numbers, not the tick marks. There is one more tick mark than there are steps.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. An improper fraction has more parts than one whole. Divide the top by the bottom to find how many whole ones it holds.
- Divide 17 by 5. The fraction line means divide. The answer tells us how many whole ones we can make.17 ÷ 5 = 3 remainder 2
- The whole number is 3. 3 lots of 5 fifths make 3 whole ones: 3 × 5 = 15.17 − 15 = 2 fifths are left over.
- Write the leftover parts as a fraction. The remainder is the numerator. The denominator stays 5.3 and
= 32 5 2 5
Check. Change back: 3 × 5 + 2 = 17 = 17. ✓
Watch out. The leftover (remainder) goes on top of the same denominator. Do not put it over the whole number.
So the missing number is 2.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. An improper fraction has more parts than one whole. Divide the top by the bottom to find how many whole ones it holds.
- Divide 23 by 4. The fraction line means divide. The answer tells us how many whole ones we can make.23 ÷ 4 = 5 remainder 3
- The whole number is 5. 5 lots of 4 quarters make 5 whole ones: 5 × 4 = 20.23 − 20 = 3 quarters are left over.
- Write the leftover parts as a fraction. The remainder is the numerator. The denominator stays 4.5 and
= 53 4 3 4
Check. Change back: 5 × 4 + 3 = 23 = 23. ✓
Watch out. The leftover (remainder) goes on top of the same denominator. Do not put it over the whole number.
So the missing number is 5.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count how many parts there are altogether. A whole number is worth the denominator in parts.
- Change the 2 wholes into eighths. One whole is
, so 2 wholes are 2 lots of 8.8 8 2 × 8 = 16, so 2 =16 8 - Add the 3 extra eighths. The fraction part is already in the same size parts.16 + 3 = 19
- Write the improper fraction. The denominator stays the same.2
=3 8 19 8
Check. Change back: 19 ÷ 8 = 2 remainder 3, so
Watch out. Multiply the whole number by the denominator, then add the numerator. Do not just write the digits next to each other.
So the missing number is 19.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count how many parts there are altogether. A whole number is worth the denominator in parts.
- Change the 4 wholes into sixths. One whole is
, so 4 wholes are 4 lots of 6.6 6 4 × 6 = 24, so 4 =24 6 - Add the 1 extra sixths. The fraction part is already in the same size parts.24 + 1 = 25
- Write the improper fraction. The denominator stays the same.4
=1 6 25 6
Check. Change back: 25 ÷ 6 = 4 remainder 1, so
Watch out. Multiply the whole number by the denominator, then add the numerator. Do not just write the digits next to each other.
So the missing number is 25.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 5, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+3 5 =4 5 =3 + 4 5 7 5 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 7 ÷ 5.7 5 = 17 5 2 5 - Write the answer.
+3 5 = 14 5 2 5
Check. Take away: 1
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 4, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+3 4 =3 4 =3 + 3 4 6 4 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 6 ÷ 4.6 4 = 16 4 2 4 - Simplify the fraction part. 2 and 4 can both be divided by 2.
=2 4 =2 ÷ 2 4 ÷ 2 1 2
So the answer is 1 .1 2 - Write the answer.
+3 4 = 13 4 1 2
Check. Take away: 1
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 6, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+5 6 =5 6 =5 + 5 6 10 6 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 10 ÷ 6.10 6 = 110 6 4 6 - Simplify the fraction part. 4 and 6 can both be divided by 2.
=4 6 =4 ÷ 2 6 ÷ 2 2 3
So the answer is 1 .2 3 - Write the answer.
+5 6 = 15 6 2 3
Check. Take away: 1
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 10, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+7 10 =9 10 =7 + 9 10 16 10 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 16 ÷ 10.16 10 = 116 10 6 10 - Simplify the fraction part. 6 and 10 can both be divided by 2.
=6 10 =6 ÷ 2 10 ÷ 2 3 5
So the answer is 1 .3 5 - Write the answer.
+7 10 = 19 10 3 5
Check. Take away: 1
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. The denominators are the same, so compare the numerators.
- Write the mixed numbers as improper fractions. This makes every number a fraction, so we can compare them.3
=1 5 =3 × 5 + 1 5 16 5 - Look at the denominators. If the bottom numbers are the same, the parts are the same size.Both are 5, so we can compare the top numbers.
- Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.17 > 16
- Write the answer. Use the original fractions in your answer.
> 317 5 1 5
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. The denominators are the same, so compare the numerators.
- Write the mixed numbers as improper fractions. This makes every number a fraction, so we can compare them.2
=3 4 =2 × 4 + 3 4 11 4 - Look at the denominators. If the bottom numbers are the same, the parts are the same size.Both are 4, so we can compare the top numbers.
- Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.11 > 10
- Write the answer. Use the original fractions in your answer.2
>3 4 10 4
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. The denominators are the same, so compare the numerators.
- Write the mixed numbers as improper fractions. This makes every number a fraction, so we can compare them.1
=1 3 =1 × 3 + 1 3 4 3 - Look at the denominators. If the bottom numbers are the same, the parts are the same size.Both are 3, so we can compare the top numbers.
- Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.5 > 4
- Write the answer. Use the original fractions in your answer.
> 15 3 1 3
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. The line in a fraction means divide. So
Method. The fraction line means divide. So a ÷ b is the fraction a over b. If the top is bigger, change it to a mixed number.
- Write the division as a fraction. A fraction line means divide, so the top number is the number being shared.3 ÷ 4 =
3 4 - Think of sharing. Cut each of the 3 wholes into 4 equal parts. Each person gets 1 part of each whole.3 parts of size
make1 4 .3 4 - Write the answer.
3 4
Check. Multiply back:
Watch out. Put the number you are dividing (the one being shared) on the top.
Key words. The line in a fraction means divide. So
Method. The fraction line means divide. So a ÷ b is the fraction a over b. If the top is bigger, change it to a mixed number.
- Write the division as a fraction. A fraction line means divide, so the top number is the number being shared.5 ÷ 8 =
5 8 - Think of sharing. Cut each of the 5 wholes into 8 equal parts. Each person gets 1 part of each whole.5 parts of size
make1 8 .5 8 - Write the answer.
5 8
Check. Multiply back:
Watch out. Put the number you are dividing (the one being shared) on the top.
Key words. The line in a fraction means divide. So
Method. The fraction line means divide. So a ÷ b is the fraction a over b. If the top is bigger, change it to a mixed number.
- Write the division as a fraction. A fraction line means divide, so the top number is the number being shared.7 ÷ 4 =
7 4 - Change it to a mixed number. 7 wholes shared between 4: each gets 1 whole, and 3 wholes are left to share.7 ÷ 4 = 1 remainder 3
- Write the left-over part as a fraction. The 3 left over are shared between 4, so each gets
.3 4 1 and = 13 4 3 4 - Write the answer. 1
3 4
Check. Multiply back: 1
Watch out. Put the number you are dividing (the one being shared) on the top.
Key words. The line in a fraction means divide. So
Method. The fraction line means divide. So a ÷ b is the fraction a over b. If the top is bigger, change it to a mixed number.
- Write the division as a fraction. A fraction line means divide, so the top number is the number being shared.11 ÷ 3 =
11 3 - Change it to a mixed number. 11 wholes shared between 3: each gets 3 wholes, and 2 wholes are left to share.11 ÷ 3 = 3 remainder 2
- Write the left-over part as a fraction. The 2 left over are shared between 3, so each gets
.2 3 3 and = 32 3 2 3 - Write the answer. 3
2 3
Check. Multiply back: 3
Watch out. Put the number you are dividing (the one being shared) on the top.
Key words. The line in a fraction means divide. So
Method. The fraction line means divide. So a ÷ b is the fraction a over b. If the top is bigger, change it to a mixed number.
- Write the division as a fraction. A fraction line means divide, so the top number is the number being shared.3 ÷ 4 =
3 4 - Think of sharing. Cut each of the 3 wholes into 4 equal parts. Each person gets 1 part of each whole.3 parts of size
make1 4 .3 4 - Write the answer.
3 4
Check. Multiply back:
Watch out. Put the number you are dividing (the one being shared) on the top.
Key words. The line in a fraction means divide. So
Method. The fraction line means divide. So a ÷ b is the fraction a over b. If the top is bigger, change it to a mixed number.
- Write the division as a fraction. A fraction line means divide, so the top number is the number being shared.9 ÷ 4 =
9 4 - Change it to a mixed number. 9 wholes shared between 4: each gets 2 wholes, and 1 whole are left to share.9 ÷ 4 = 2 remainder 1
- Write the left-over part as a fraction. The 1 left over are shared between 4, so each gets
.1 4 2 and = 21 4 1 4 - Write the answer. 2
1 4
Check. Multiply back: 2
Watch out. Put the number you are dividing (the one being shared) on the top.
Key words. The line in a fraction means divide. So
Method. The fraction line means divide. So a ÷ b is the fraction a over b. If the top is bigger, change it to a mixed number.
- Write the division as a fraction. A fraction line means divide, so the top number is the number being shared.5 ÷ 3 =
5 3 - Change it to a mixed number. 5 wholes shared between 3: each gets 1 whole, and 2 wholes are left to share.5 ÷ 3 = 1 remainder 2
- Write the left-over part as a fraction. The 2 left over are shared between 3, so each gets
.2 3 1 and = 12 3 2 3 - Write the answer. 1
2 3
Check. Multiply back: 1
Watch out. Put the number you are dividing (the one being shared) on the top.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count how many parts there are altogether. A whole number is worth the denominator in parts.
- Change the 4 wholes into halves. One whole is
, so 4 wholes are 4 lots of 2.2 2 4 × 2 = 8, so 4 =8 2 - Add the 1 extra halves. The fraction part is already in the same size parts.8 + 1 = 9
- Write the improper fraction. The denominator stays the same.4
=1 2 9 2
Check. Change back: 9 ÷ 2 = 4 remainder 1, so
Watch out. Multiply the whole number by the denominator, then add the numerator. Do not just write the digits next to each other.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Work out the value of each one in its simplest form. Three will be the same. The odd one out is the one that is different.
- Write each one in its simplest form. Then equal values are easy to spot.
= 17 4 3 4
1 = 13 4 3 4 = 114 8 3 4
1 = 17 8 7 8 - Find the one that is different. The other three have the same value.1
is the odd one out.7 8
Check. Check the three that match once more. ✓
Watch out. Compare values, not the look of the numbers.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Work the question out yourself first. Then compare your working with the working in the question and find where it goes wrong.
- Work it out correctly. We need the right answer to compare with.3
: 3 × 5 + 2 = 17, so2 5 .17 5 - Find the mistake. Noah multiplied 3 × 2 = 6 and put it over 5. But the whole number 3 must be multiplied by the bottom number 5, then the top number 2 is added.Noah says 3
=2 5 .6 5 - Write the correct answer. The correct answer is
. (17 5 is only 16 5 , which is smaller than 31 5 .)2 5
Check. 17 ÷ 5 = 3 remainder 2, so 3
Watch out. Whole number × bottom number, then add the top number.
Key words. Always means true every time. Never means false every time. Sometimes means true for some numbers and false for others.
Method. Test the statement with some numbers. If it is always true, never true, or true for some numbers only, that gives the answer.
- Try some examples. Testing numbers helps us see if the statement is true every time.
is more than 1 whole (7 > 5).7 5 - Look for an example that does not work. One example that breaks the rule is a counter-example.
is an improper fraction but it is equal to 1, not more than 1.5 5 - Decide: always, sometimes or never? An improper fraction is 1 or more. It is more than 1 unless the top and the bottom are equal.Sometimes
Check. We found a fraction that is more than 1 and one that is not. ✓
Watch out. To show a statement is “always” true you need a reason. A few examples are not enough to prove it, but one counter-example shows it is not always true.
Key words. Always means true every time. Never means false every time. Sometimes means true for some numbers and false for others.
Method. Test the statement with some numbers. If it is always true, never true, or true for some numbers only, that gives the answer.
- Try some examples. Testing numbers helps us see if the statement is true every time.1
is more than 11 2
2 is more than 23 4
5 is more than 51 10 - Decide: always, sometimes or never? A mixed number is a whole number (1 or more) plus a fraction, so it is always bigger than its whole number part, and so more than 1.Always
Check. Every example is more than 1. ✓
Watch out. To show a statement is “always” true you need a reason. A few examples are not enough to prove it, but one counter-example shows it is not always true.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. The fraction is between 2 and 3 and its denominator is 6. Find the range for the numerator, then pick the multiple of 5.
- Find the numerators that give numbers between 2 and 3. 2 = 12 sixths and 3 = 18 sixths.2 =
and 3 =12 6 , so the numerator is between 12 and 18.18 6 - List the multiples of 5 in that range. The numerator must be a multiple of 5.13, 14, 15, 16, 17: only 15 is a multiple of 5.
- Write the fraction.
= 215 6 = 23 6 1 2
Check. 2
Watch out. The numerator is greater than 12 and less than 18. The numbers 12 and 18 themselves would be whole numbers.
Adding and subtracting fractions
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
When the denominators are the same, the parts are the same size, so we just add the numerators.
If the answer is more than 1, write it as a mixed number:
What if the denominators are different, like
Key ideas
- Same denominator: add (or subtract) the numerators and keep the denominator.
- Different denominators: change to a common denominator first (use the bigger denominator when it is a multiple of the other).
- If the answer is an improper fraction, write it as a mixed number:
= 16 5 .1 5 - Always simplify at the end:
=4 6 .2 3 - From a whole: write the whole as a fraction first: 1 =
.8 8
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 8, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+3 8 =2 8 =3 + 2 8 5 8 - Write the answer. It is already in its simplest form.
5 8
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 4, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+3 4 =3 4 =3 + 3 4 6 4 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 6 ÷ 4.6 4 = 16 4 2 4 - Simplify the fraction part. 2 and 4 can both be divided by 2.
=2 4 =2 ÷ 2 4 ÷ 2 1 2
So the answer is 1 .1 2 - Write the answer.
+3 4 = 13 4 1 2
Check. Take away: 1
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 4, so 4 will do.4 ÷ 2 = 2, so 2 goes into 4
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=1 2 =1 × 2 2 × 2 2 4 - Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+2 4 =1 4 =2 + 1 4 3 4 - Write the answer.
+1 2 =1 4 3 4
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 6, so 6 will do.6 ÷ 3 = 2, so 3 goes into 6
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=2 3 =2 × 2 3 × 2 4 6 - Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+4 6 =1 6 =4 + 1 6 5 6 - Write the answer.
+2 3 =1 6 5 6
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 12, so 12 will do.12 ÷ 4 = 3, so 4 goes into 12
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=1 4 =1 × 3 4 × 3 3 12 - Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+7 12 =3 12 =7 + 3 12 10 12 - Simplify the fraction part. 10 and 12 can both be divided by 2.
=10 12 =10 ÷ 2 12 ÷ 2 5 6 - Write the answer.
+7 12 =1 4 5 6
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then subtract the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=3 5 =3 × 2 5 × 2 6 10 - Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−6 10 =1 10 =6 − 1 10 5 10 - Simplify the fraction part. 5 and 10 can both be divided by 5.
=5 10 =5 ÷ 5 10 ÷ 5 1 2 - Write the answer.
−3 5 =1 10 1 2
Check. Add back:
Watch out. Subtract the numerators only. The denominator stays the same.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then subtract the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 6, so 6 will do.6 ÷ 3 = 2, so 3 goes into 6
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=1 3 =1 × 2 3 × 2 2 6 - Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−5 6 =2 6 =5 − 2 6 3 6 - Simplify the fraction part. 3 and 6 can both be divided by 3.
=3 6 =3 ÷ 3 6 ÷ 3 1 2 - Write the answer.
−5 6 =1 3 1 2
Check. Add back:
Watch out. Subtract the numerators only. The denominator stays the same.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- The first fraction part (0) is smaller than the second (3), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 8 eighths, so the numbers become fractions over 8.1
=0 8 =1 × 8 + 0 8 8 8 =3 8 =0 × 8 + 3 8 3 8 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−8 8 =3 8 =8 − 3 8 5 8 - Write the answer. It is already in its simplest form.
5 8
Check. Add back:
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Watch out
Add the numerators only. Do not add the denominators:Exercise 6E Adding and subtracting fractions
Non-calculatorKey words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 7, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+2 7 =3 7 =2 + 3 7 5 7 - Write the answer. It is already in its simplest form.
5 7
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 9, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+1 9 =4 9 =1 + 4 9 5 9 - Write the answer. It is already in its simplest form.
5 9
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 12, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+5 12 =3 12 =5 + 3 12 8 12 - Simplify the fraction part. 8 and 12 can both be divided by 4.
=8 12 =8 ÷ 4 12 ÷ 4 2 3 - Write the answer.
+5 12 =3 12 2 3
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 10, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+3 10 =4 10 =3 + 4 10 7 10 - Write the answer. It is already in its simplest form.
7 10
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then subtract the numerators and keep the denominator.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 9, so we can subtract straight away.
- Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−7 9 =4 9 =7 − 4 9 3 9 - Simplify the fraction part. 3 and 9 can both be divided by 3.
=3 9 =3 ÷ 3 9 ÷ 3 1 3 - Write the answer.
−7 9 =4 9 1 3
Check. Add back:
Watch out. Subtract the numerators only. The denominator stays the same.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then subtract the numerators and keep the denominator.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 10, so we can subtract straight away.
- Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−8 10 =3 10 =8 − 3 10 5 10 - Simplify the fraction part. 5 and 10 can both be divided by 5.
=5 10 =5 ÷ 5 10 ÷ 5 1 2 - Write the answer.
−8 10 =3 10 1 2
Check. Add back:
Watch out. Subtract the numerators only. The denominator stays the same.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then subtract the numerators and keep the denominator.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 6, so we can subtract straight away.
- Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−5 6 =1 6 =5 − 1 6 4 6 - Simplify the fraction part. 4 and 6 can both be divided by 2.
=4 6 =4 ÷ 2 6 ÷ 2 2 3 - Write the answer.
−5 6 =1 6 2 3
Check. Add back:
Watch out. Subtract the numerators only. The denominator stays the same.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then subtract the numerators and keep the denominator.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 12, so we can subtract straight away.
- Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−11 12 =7 12 =11 − 7 12 4 12 - Simplify the fraction part. 4 and 12 can both be divided by 4.
=4 12 =4 ÷ 4 12 ÷ 4 1 3 - Write the answer.
−11 12 =7 12 1 3
Check. Add back:
Watch out. Subtract the numerators only. The denominator stays the same.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 4, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+3 4 =3 4 =3 + 3 4 6 4 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 6 ÷ 4.6 4 = 16 4 2 4 - Simplify the fraction part. 2 and 4 can both be divided by 2.
=2 4 =2 ÷ 2 4 ÷ 2 1 2
So the answer is 1 .1 2 - Write the answer.
+3 4 = 13 4 1 2
Check. Take away: 1
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 5, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+4 5 =3 5 =4 + 3 5 7 5 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 7 ÷ 5.7 5 = 17 5 2 5 - Write the answer.
+4 5 = 13 5 2 5
Check. Take away: 1
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 8, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+5 8 =7 8 =5 + 7 8 12 8 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 12 ÷ 8.12 8 = 112 8 4 8 - Simplify the fraction part. 4 and 8 can both be divided by 4.
=4 8 =4 ÷ 4 8 ÷ 4 1 2
So the answer is 1 .1 2 - Write the answer.
+5 8 = 17 8 1 2
Check. Take away: 1
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 10, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+7 10 =9 10 =7 + 9 10 16 10 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 16 ÷ 10.16 10 = 116 10 6 10 - Simplify the fraction part. 6 and 10 can both be divided by 2.
=6 10 =6 ÷ 2 10 ÷ 2 3 5
So the answer is 1 .3 5 - Write the answer.
+7 10 = 19 10 3 5
Check. Take away: 1
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 8, so we can add straight away.
- Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+3 8 =4 8 =3 + 4 8 7 8 - Write the answer. It is already in its simplest form.
7 8
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then subtract the numerators and keep the denominator.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 10, so we can subtract straight away.
- Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−7 10 =3 10 =7 − 3 10 4 10 - Simplify the fraction part. 4 and 10 can both be divided by 2.
=4 10 =4 ÷ 2 10 ÷ 2 2 5 - Write the answer.
−7 10 =3 10 2 5
Check. Add back:
Watch out. Subtract the numerators only. The denominator stays the same.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 4, so 4 will do.4 ÷ 2 = 2, so 2 goes into 4
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=1 2 =1 × 2 2 × 2 2 4 - Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+2 4 =1 4 =2 + 1 4 3 4 - Write the answer.
+1 2 =1 4 3 4
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 6, so 6 will do.6 ÷ 3 = 2, so 3 goes into 6
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=1 3 =1 × 2 3 × 2 2 6 - Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+2 6 =1 6 =2 + 1 6 3 6 - Simplify the fraction part. 3 and 6 can both be divided by 3.
=3 6 =3 ÷ 3 6 ÷ 3 1 2 - Write the answer.
+1 3 =1 6 1 2
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=1 5 =1 × 2 5 × 2 2 10 - Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+3 10 =2 10 =3 + 2 10 5 10 - Simplify the fraction part. 5 and 10 can both be divided by 5.
=5 10 =5 ÷ 5 10 ÷ 5 1 2 - Write the answer.
+3 10 =1 5 1 2
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 12, so 12 will do.12 ÷ 3 = 4, so 3 goes into 12
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=1 3 =1 × 4 3 × 4 4 12 - Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+5 12 =4 12 =5 + 4 12 9 12 - Simplify the fraction part. 9 and 12 can both be divided by 3.
=9 12 =9 ÷ 3 12 ÷ 3 3 4 - Write the answer.
+5 12 =1 3 3 4
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then subtract the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=3 4 =3 × 2 4 × 2 6 8 - Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−6 8 =1 8 =6 − 1 8 5 8 - Write the answer.
−3 4 =1 8 5 8
Check. Add back:
Watch out. Subtract the numerators only. The denominator stays the same.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then subtract the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 6, so 6 will do.6 ÷ 3 = 2, so 3 goes into 6
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=1 3 =1 × 2 3 × 2 2 6 - Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−5 6 =2 6 =5 − 2 6 3 6 - Simplify the fraction part. 3 and 6 can both be divided by 3.
=3 6 =3 ÷ 3 6 ÷ 3 1 2 - Write the answer.
−5 6 =1 3 1 2
Check. Add back:
Watch out. Subtract the numerators only. The denominator stays the same.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then subtract the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=2 5 =2 × 2 5 × 2 4 10 - Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−7 10 =4 10 =7 − 4 10 3 10 - Write the answer.
−7 10 =2 5 3 10
Check. Add back:
Watch out. Subtract the numerators only. The denominator stays the same.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then subtract the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=3 5 =3 × 2 5 × 2 6 10 - Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−6 10 =1 10 =6 − 1 10 5 10 - Simplify the fraction part. 5 and 10 can both be divided by 5.
=5 10 =5 ÷ 5 10 ÷ 5 1 2 - Write the answer.
−3 5 =1 10 1 2
Check. Add back:
Watch out. Subtract the numerators only. The denominator stays the same.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- The first fraction part (0) is smaller than the second (1), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 4 quarters, so the numbers become fractions over 4.1
=0 4 =1 × 4 + 0 4 4 4 =1 4 =0 × 4 + 1 4 1 4 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−4 4 =1 4 =4 − 1 4 3 4 - Write the answer. It is already in its simplest form.
3 4
Check. Add back:
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- The first fraction part (0) is smaller than the second (3), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 5 fifths, so the numbers become fractions over 5.1
=0 5 =1 × 5 + 0 5 5 5 =3 5 =0 × 5 + 3 5 3 5 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−5 5 =3 5 =5 − 3 5 2 5 - Write the answer. It is already in its simplest form.
2 5
Check. Add back:
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- The first fraction part (0) is smaller than the second (7), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 12 twelfths, so the numbers become fractions over 12.1
=0 12 =1 × 12 + 0 12 12 12 =7 12 =0 × 12 + 7 12 7 12 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−12 12 =7 12 =12 − 7 12 5 12 - Write the answer. It is already in its simplest form.
5 12
Check. Add back:
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- The first fraction part (0) is smaller than the second (3), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 4 quarters, so the numbers become fractions over 4.2
=0 4 =2 × 4 + 0 4 8 4 =3 4 =0 × 4 + 3 4 3 4 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−8 4 =3 4 =8 − 3 4 5 4 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 5 ÷ 4.5 4 = 15 4 1 4 - Write the answer. 2 −
= 13 4 1 4
Check. Add back: 1
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Use the inverse (opposite) operation to find the missing number.
- Choose the operation. We know
+ ? =2 5 . The missing number is what is left when we take4 5 from2 5 .4 5 −4 5 =2 5 2 5 - Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 5, so we can subtract straight away.
- Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−4 5 =2 5 =4 − 2 5 2 5 - Write the answer. It is already in its simplest form.
2 5
Check. Put it back in:
Watch out. The missing number is not always the first or second number. Use the opposite operation.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Use the inverse (opposite) operation to find the missing number.
- Choose the operation. We know
+ ? =1 4 . The missing number is what is left when we take5 8 from1 4 .5 8 −5 8 =1 4 3 8 - Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=1 4 =1 × 2 4 × 2 2 8 - Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−5 8 =2 8 =5 − 2 8 3 8 - Write the answer.
−5 8 =1 4 3 8
Check. Put it back in:
Watch out. The missing number is not always the first or second number. Use the opposite operation.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Use the inverse (opposite) operation to find the missing number.
- Choose the operation. We know ? −
=1 4 . To undo the subtraction, add1 2 to1 4 .1 2 +1 2 =1 4 3 4 - Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 4, so 4 will do.4 ÷ 2 = 2, so 2 goes into 4
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=1 2 =1 × 2 2 × 2 2 4 - Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+2 4 =1 4 =2 + 1 4 3 4 - Write the answer.
+1 2 =1 4 3 4
Check. Put it back in:
Watch out. The missing number is not always the first or second number. Use the opposite operation.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Use the inverse (opposite) operation to find the missing number.
- Choose the operation. We know
− ? =7 8 . The missing number is the difference between3 8 and7 8 .3 8 −7 8 =3 8 1 2 - Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 8, so we can subtract straight away.
- Subtract the numerators. We are taking parts of the same size away, so subtract the top numbers. The bottom number stays the same.
−7 8 =3 8 =7 − 3 8 4 8 - Simplify the fraction part. 4 and 8 can both be divided by 4.
=4 8 =4 ÷ 4 8 ÷ 4 1 2 - Write the answer.
−7 8 =3 8 1 2
Check. Put it back in:
Watch out. The missing number is not always the first or second number. Use the opposite operation.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Use the inverse (opposite) operation to find the missing number.
- Choose the operation. We know 1 − ? =
. The missing number is the difference between 1 and2 7 .2 7 1 − =2 7 5 7 - The first fraction part (0) is smaller than the second (2), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 7 sevenths, so the numbers become fractions over 7.1
=0 7 =1 × 7 + 0 7 7 7 =2 7 =0 × 7 + 2 7 2 7 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−7 7 =2 7 =7 − 2 7 5 7 - Write the answer. It is already in its simplest form.
5 7
Check. Put it back in: 1 −
Watch out. The missing number is not always the first or second number. Use the opposite operation.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=1 4 =1 × 2 4 × 2 2 8 - Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+2 8 =3 8 =2 + 3 8 5 8 - Write the answer.
+1 4 =3 8 5 8
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- The first fraction part (0) is smaller than the second (5), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 8 eighths, so the numbers become fractions over 8.1
=0 8 =1 × 8 + 0 8 8 8 =5 8 =0 × 8 + 5 8 5 8 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−8 8 =5 8 =8 − 5 8 3 8 - Write the answer. It is already in its simplest form.
3 8
Check. Add back:
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=3 4 =3 × 2 4 × 2 6 8 - Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+6 8 =5 8 =6 + 5 8 11 8 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 11 ÷ 8.11 8 = 111 8 3 8 - Write the answer.
+3 4 = 15 8 3 8
Check. Take away: 1
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 6, so 6 will do.6 ÷ 3 = 2, so 3 goes into 6
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=2 3 =2 × 2 3 × 2 4 6 - Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+4 6 =1 6 =4 + 1 6 5 6 - Write the answer.
+2 3 =1 6 5 6
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Work the question out yourself first. Then compare your working with the working in the question and find where it goes wrong.
- Work it out correctly. We need the right answer to compare with.
=1 2 and3 6 =1 3 , so2 6 +3 6 =2 6 .5 6 - Find the mistake. Amy added the tops (1 + 1 = 2) and the bottoms (2 + 3 = 5). But the denominators tell us the size of the parts, so they must not be added. Halves and thirds are different sizes, so she needed a common denominator.Amy wrote
+1 2 =1 3 .2 5 - Write the correct answer. The correct answer is
.5 6
Check.
Watch out. Never add the denominators.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Work the question out yourself first. Then compare your working with the working in the question and find where it goes wrong.
- Work it out correctly. We need the right answer to compare with.
+3 4 =3 4 = 16 4 = 12 4 .1 2 - Find the mistake. Jack added the denominators (4 + 4 = 8). The parts are quarters before and after adding, so the denominator stays 4.Jack wrote
+3 4 =3 4 .6 8 - Write the correct answer. The correct answer is 1
. (1 2 is less than 1, but two three-quarters must be more than 1.)6 8
Check. 1
Watch out. Add the numerators. Keep the denominator.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. To make 1 whole, two fractions must add up to eight eighths. Change every fraction to eighths and look for pairs that make 8.
- Write each fraction in eighths. All the denominators are 2, 4 or 8, so 8 works for all of them.
=1 4 ,2 8 =3 8 ,3 8 =5 8 ,5 8 =1 2 ,4 8 =3 4 6 8 - Find the pairs that add up to 8 eighths. The numerators of a pair must add up to 8.2 + 6 = 8 →
and1 4 3 4
3 + 5 = 8 → and3 8 5 8
(4 + 4 = 8 would need two halves, but there is only one ½.) - Write the pairs.
and1 4 ,3 4 and3 8 5 8
Check.
Watch out. There is only one one-half in the list, so half and half does not count.
Key words. Always means true every time. Never means false every time. Sometimes means true for some numbers and false for others.
Method. Test the statement with some numbers. If it is always true, never true, or true for some numbers only, that gives the answer.
- Try some examples. Testing numbers helps us see if the statement is true every time.
+1 4 =1 4 , which is less than 1.1 2 - Look for an example that does not work. One example that breaks the rule is a counter-example.
+3 4 = 13 4 , which is more than 1.1 2 - Decide: always, sometimes or never? It depends on the two fractions. Small fractions add to less than 1 and big ones can add to more than 1.Sometimes
Check. We found one of each. ✓
Watch out. To show a statement is “always” true you need a reason. A few examples are not enough to prove it, but one counter-example shows it is not always true.
Key words. Always means true every time. Never means false every time. Sometimes means true for some numbers and false for others.
Method. Test the statement with some numbers. If it is always true, never true, or true for some numbers only, that gives the answer.
- Try some examples. Testing numbers helps us see if the statement is true every time.1 −
=1 4 , less than 13 4
1 − =3 5 , less than 12 5
1 − =9 10 , less than 11 10 - Decide: always, sometimes or never? You take away a part, so there is less than a whole left.Always
Check. All the answers are less than 1. ✓
Watch out. To show a statement is “always” true you need a reason. A few examples are not enough to prove it, but one counter-example shows it is not always true.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Change all three fractions to the same denominator (sixths) and add the numerators.
- Find a common denominator. 2, 3 and 6 all go into 6.6 ÷ 2 = 3, 6 ÷ 3 = 2, 6 ÷ 6 = 1
- Change each fraction to sixths. Multiply the top and the bottom by the same number.
=1 2 3 6 =1 3 2 6 =1 6 1 6 - Add the numerators. The denominator stays 6.
+3 6 +2 6 =1 6 =3 + 2 + 1 6 6 6 - Write the conclusion. A “show that” question needs a sentence at the end.
= 1, so Sofia is correct:6 6 +1 2 +1 3 = 1.1 6
Check. Half a pizza, a third and a sixth fill the whole pizza. ✓
Watch out. Show each conversion. Do not just write the answer.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Add the two fractions you know, then take the total away from the answer 3/4. Use twelfths.
- Write every fraction in twelfths. 3, 4 and 12 all go into 12.
=1 3 ,4 12 =1 12 ,1 12 =3 4 9 12 - Add the two known fractions. The missing fraction plus these two make the total.
+4 12 =1 12 5 12 - Take the known part from the total. What is left is the missing fraction.
−9 12 =5 12 4 12 - Simplify. 4 and 12 can both be divided by 4.
=4 12 1 3
Check.
Watch out. Change everything to the same denominator before you start.
Adding and subtracting mixed numbers
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
To add mixed numbers, add the whole numbers first, then add the fractions. Put the answers together. 2
Crossing a whole. If the fractions add to 1 or more, you must carry a whole. 2
Subtracting. If the fraction of the first number is big enough, subtract the wholes and the fractions separately: 4
Key ideas
- Add: add the wholes, add the fractions (same denominator first), then put them together.
- If the fractions add to 1 or more, change the fraction part to a whole and a fraction and add the whole.
- Subtract: if the first fraction is big enough, subtract wholes and fractions separately.
- If the fraction you take away is bigger, change both numbers to improper fractions, subtract, then change back to a mixed number.
- Always simplify the fraction at the end.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 5, so we can add straight away.
- Add the whole numbers. Add the wholes first, then deal with the fractions.2 + 1 = 3
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+1 5 =2 5 =1 + 2 5 3 5 - Write the answer. 2
+ 11 5 = 32 5 3 5
Check. Take away: 3
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 4, so we can add straight away.
- Add the whole numbers. Add the wholes first, then deal with the fractions.2 + 1 = 3
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+3 4 =3 4 =3 + 3 4 6 4 - The fraction part is 1 or more, so change it to a whole number and a fraction.
means 6 ÷ 4.6 4 = 16 4 2 4
3 + 1 = 42 4 2 4 - Simplify the fraction part. 2 and 4 can both be divided by 2.
=2 4 =2 ÷ 2 4 ÷ 2 1 2
So the answer is 4 .1 2 - Write the answer. 2
+ 13 4 = 43 4 1 2
Check. Take away: 4
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 4, so 4 will do.4 ÷ 2 = 2, so 2 goes into 4
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.3
→1 2 =1 2 =1 × 2 2 × 2 2 4 - Add the whole numbers. Add the wholes first, then deal with the fractions.3 + 2 = 5
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+2 4 =1 4 =2 + 1 4 3 4 - Write the answer. 3
+ 21 2 = 51 4 3 4
Check. Take away: 5
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 6, so 6 will do.6 ÷ 3 = 2, so 3 goes into 6
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.2
→1 3 =1 3 =1 × 2 3 × 2 2 6 - Add the whole numbers. Add the wholes first, then deal with the fractions.1 + 2 = 3
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+5 6 =2 6 =5 + 2 6 7 6 - The fraction part is 1 or more, so change it to a whole number and a fraction.
means 7 ÷ 6.7 6 = 17 6 1 6
3 + 1 = 41 6 1 6 - Write the answer. 1
+ 25 6 = 41 3 1 6
Check. Take away: 4
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 6, so we can subtract straight away.
- Subtract the whole numbers. The fraction part of the first number is big enough, so we can subtract the wholes and the fractions separately.4 − 1 = 3
- Subtract the fractions. Subtract the numerators. The denominator stays the same.
−5 6 =1 6 4 6 - Simplify the fraction part. 4 and 6 can both be divided by 2.
=4 6 =4 ÷ 2 6 ÷ 2 2 3
So the answer is 3 .2 3 - Write the answer. 4
− 15 6 = 31 6 2 3
Check. Add back: 3
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.2
→3 4 =3 4 =3 × 2 4 × 2 6 8 - Subtract the whole numbers. The fraction part of the first number is big enough, so we can subtract the wholes and the fractions separately.5 − 2 = 3
- Subtract the fractions. Subtract the numerators. The denominator stays the same.
−7 8 =6 8 1 8 - Write the answer. 5
− 27 8 = 33 4 1 8
Check. Add back: 3
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 5, so we can subtract straight away.
- The first fraction part (1) is smaller than the second (3), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 5 fifths, so the numbers become fractions over 5.3
=1 5 =3 × 5 + 1 5 16 5
1 =3 5 =1 × 5 + 3 5 8 5 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−16 5 =8 5 =16 − 8 5 8 5 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 8 ÷ 5.8 5 = 18 5 3 5 - Write the answer. 3
− 11 5 = 13 5 3 5
Check. Add back: 1
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- The first fraction part (0) is smaller than the second (3), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 8 eighths, so the numbers become fractions over 8.4
=0 8 =4 × 8 + 0 8 32 8
1 =3 8 =1 × 8 + 3 8 11 8 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−32 8 =11 8 =32 − 11 8 21 8 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 21 ÷ 8.21 8 = 221 8 5 8 - Write the answer. 4 − 1
= 23 8 5 8
Check. Add back: 2
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 4, so 4 will do.4 ÷ 2 = 2, so 2 goes into 4
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=1 2 =1 × 2 2 × 2 2 4 - The first fraction part (1) is smaller than the second (2), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 4 quarters, so the numbers become fractions over 4.2
=1 4 =2 × 4 + 1 4 9 4 =2 4 =0 × 4 + 2 4 2 4 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−9 4 =2 4 =9 − 2 4 7 4 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 7 ÷ 4.7 4 = 17 4 3 4 - Write the answer. 2
−1 4 = 11 2 3 4
Check. Add back: 1
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Watch out
Do not take the smaller fraction from the bigger one in each column. 3Exercise 6F Adding and subtracting mixed numbers
Non-calculatorKey words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 5, so we can add straight away.
- Add the whole numbers. Add the wholes first, then deal with the fractions.1 + 2 = 3
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+1 5 =2 5 =1 + 2 5 3 5 - Write the answer. 1
+ 21 5 = 32 5 3 5
Check. Take away: 3
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 7, so we can add straight away.
- Add the whole numbers. Add the wholes first, then deal with the fractions.3 + 1 = 4
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+2 7 =3 7 =2 + 3 7 5 7 - Write the answer. 3
+ 12 7 = 43 7 5 7
Check. Take away: 4
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 8, so we can add straight away.
- Add the whole numbers. Add the wholes first, then deal with the fractions.2 + 4 = 6
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+1 8 =3 8 =1 + 3 8 4 8 - Simplify the fraction part. 4 and 8 can both be divided by 4.
=4 8 =4 ÷ 4 8 ÷ 4 1 2
So the answer is 6 .1 2 - Write the answer. 2
+ 41 8 = 63 8 1 2
Check. Take away: 6
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 10, so we can add straight away.
- Add the whole numbers. Add the wholes first, then deal with the fractions.5 + 2 = 7
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+3 10 =4 10 =3 + 4 10 7 10 - Write the answer. 5
+ 23 10 = 74 10 7 10
Check. Take away: 7
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 4, so we can add straight away.
- Add the whole numbers. Add the wholes first, then deal with the fractions.2 + 1 = 3
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+3 4 =3 4 =3 + 3 4 6 4 - The fraction part is 1 or more, so change it to a whole number and a fraction.
means 6 ÷ 4.6 4 = 16 4 2 4
3 + 1 = 42 4 2 4 - Simplify the fraction part. 2 and 4 can both be divided by 2.
=2 4 =2 ÷ 2 4 ÷ 2 1 2
So the answer is 4 .1 2 - Write the answer. 2
+ 13 4 = 43 4 1 2
Check. Take away: 4
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 6, so we can add straight away.
- Add the whole numbers. Add the wholes first, then deal with the fractions.3 + 2 = 5
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+5 6 =3 6 =5 + 3 6 8 6 - The fraction part is 1 or more, so change it to a whole number and a fraction.
means 8 ÷ 6.8 6 = 18 6 2 6
5 + 1 = 62 6 2 6 - Simplify the fraction part. 2 and 6 can both be divided by 2.
=2 6 =2 ÷ 2 6 ÷ 2 1 3
So the answer is 6 .1 3 - Write the answer. 3
+ 25 6 = 63 6 1 3
Check. Take away: 6
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 5, so we can add straight away.
- Add the whole numbers. Add the wholes first, then deal with the fractions.1 + 3 = 4
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+4 5 =3 5 =4 + 3 5 7 5 - The fraction part is 1 or more, so change it to a whole number and a fraction.
means 7 ÷ 5.7 5 = 17 5 2 5
4 + 1 = 52 5 2 5 - Write the answer. 1
+ 34 5 = 53 5 2 5
Check. Take away: 5
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Check the denominators. To add fractions, the parts must be the same size.Both denominators are 8, so we can add straight away.
- Add the whole numbers. Add the wholes first, then deal with the fractions.2 + 1 = 3
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+7 8 =5 8 =7 + 5 8 12 8 - The fraction part is 1 or more, so change it to a whole number and a fraction.
means 12 ÷ 8.12 8 = 112 8 4 8
3 + 1 = 44 8 4 8 - Simplify the fraction part. 4 and 8 can both be divided by 4.
=4 8 =4 ÷ 4 8 ÷ 4 1 2
So the answer is 4 .1 2 - Write the answer. 2
+ 17 8 = 45 8 1 2
Check. Take away: 4
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 4, so 4 will do.4 ÷ 2 = 2, so 2 goes into 4
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.1
→1 2 =1 2 =1 × 2 2 × 2 2 4 - Add the whole numbers. Add the wholes first, then deal with the fractions.1 + 2 = 3
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+2 4 =1 4 =2 + 1 4 3 4 - Write the answer. 1
+ 21 2 = 31 4 3 4
Check. Take away: 3
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.1
→1 5 =1 5 =1 × 2 5 × 2 2 10 - Add the whole numbers. Add the wholes first, then deal with the fractions.3 + 1 = 4
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+3 10 =2 10 =3 + 2 10 5 10 - Simplify the fraction part. 5 and 10 can both be divided by 5.
=5 10 =5 ÷ 5 10 ÷ 5 1 2
So the answer is 4 .1 2 - Write the answer. 3
+ 13 10 = 41 5 1 2
Check. Take away: 4
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 6, so 6 will do.6 ÷ 3 = 2, so 3 goes into 6
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.2
→2 3 =2 3 =2 × 2 3 × 2 4 6 - Add the whole numbers. Add the wholes first, then deal with the fractions.2 + 1 = 3
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+4 6 =5 6 =4 + 5 6 9 6 - The fraction part is 1 or more, so change it to a whole number and a fraction.
means 9 ÷ 6.9 6 = 19 6 3 6
3 + 1 = 43 6 3 6 - Simplify the fraction part. 3 and 6 can both be divided by 3.
=3 6 =3 ÷ 3 6 ÷ 3 1 2
So the answer is 4 .1 2 - Write the answer. 2
+ 12 3 = 45 6 1 2
Check. Take away: 4
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.4
→3 4 =3 4 =3 × 2 4 × 2 6 8 - Add the whole numbers. Add the wholes first, then deal with the fractions.4 + 1 = 5
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+6 8 =5 8 =6 + 5 8 11 8 - The fraction part is 1 or more, so change it to a whole number and a fraction.
means 11 ÷ 8.11 8 = 111 8 3 8
5 + 1 = 63 8 3 8 - Write the answer. 4
+ 13 4 = 65 8 3 8
Check. Take away: 6
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 6, so we can subtract straight away.
- Subtract the whole numbers. The fraction part of the first number is big enough, so we can subtract the wholes and the fractions separately.4 − 1 = 3
- Subtract the fractions. Subtract the numerators. The denominator stays the same.
−5 6 =1 6 4 6 - Simplify the fraction part. 4 and 6 can both be divided by 2.
=4 6 =4 ÷ 2 6 ÷ 2 2 3
So the answer is 3 .2 3 - Write the answer. 4
− 15 6 = 31 6 2 3
Check. Add back: 3
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 8, so we can subtract straight away.
- Subtract the whole numbers. The fraction part of the first number is big enough, so we can subtract the wholes and the fractions separately.6 − 2 = 4
- Subtract the fractions. Subtract the numerators. The denominator stays the same.
−7 8 =3 8 4 8 - Simplify the fraction part. 4 and 8 can both be divided by 4.
=4 8 =4 ÷ 4 8 ÷ 4 1 2
So the answer is 4 .1 2 - Write the answer. 6
− 27 8 = 43 8 1 2
Check. Add back: 4
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 10, so we can subtract straight away.
- Subtract the whole numbers. The fraction part of the first number is big enough, so we can subtract the wholes and the fractions separately.3 − 1 = 2
- Subtract the fractions. Subtract the numerators. The denominator stays the same.
−9 10 =4 10 5 10 - Simplify the fraction part. 5 and 10 can both be divided by 5.
=5 10 =5 ÷ 5 10 ÷ 5 1 2
So the answer is 2 .1 2 - Write the answer. 3
− 19 10 = 24 10 1 2
Check. Add back: 2
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 5, so we can subtract straight away.
- Subtract the whole numbers. The fraction part of the first number is big enough, so we can subtract the wholes and the fractions separately.5 − 2 = 3
- Subtract the fractions. Subtract the numerators. The denominator stays the same.
−4 5 =1 5 3 5 - Write the answer. 5
− 24 5 = 31 5 3 5
Check. Add back: 3
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 8, so 8 will do.8 ÷ 4 = 2, so 4 goes into 8
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.2
→3 4 =3 4 =3 × 2 4 × 2 6 8 - Subtract the whole numbers. The fraction part of the first number is big enough, so we can subtract the wholes and the fractions separately.5 − 2 = 3
- Subtract the fractions. Subtract the numerators. The denominator stays the same.
−7 8 =6 8 1 8 - Write the answer. 5
− 27 8 = 33 4 1 8
Check. Add back: 3
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 6, so 6 will do.6 ÷ 3 = 2, so 3 goes into 6
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.1
→1 3 =1 3 =1 × 2 3 × 2 2 6 - Subtract the whole numbers. The fraction part of the first number is big enough, so we can subtract the wholes and the fractions separately.3 − 1 = 2
- Subtract the fractions. Subtract the numerators. The denominator stays the same.
−5 6 =2 6 3 6 - Simplify the fraction part. 3 and 6 can both be divided by 3.
=3 6 =3 ÷ 3 6 ÷ 3 1 2
So the answer is 2 .1 2 - Write the answer. 3
− 15 6 = 21 3 1 2
Check. Add back: 2
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.2
→2 5 =2 5 =2 × 2 5 × 2 4 10 - Subtract the whole numbers. The fraction part of the first number is big enough, so we can subtract the wholes and the fractions separately.6 − 2 = 4
- Subtract the fractions. Subtract the numerators. The denominator stays the same.
−9 10 =4 10 5 10 - Simplify the fraction part. 5 and 10 can both be divided by 5.
=5 10 =5 ÷ 5 10 ÷ 5 1 2
So the answer is 4 .1 2 - Write the answer. 6
− 29 10 = 42 5 1 2
Check. Add back: 4
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 4, so 4 will do.4 ÷ 2 = 2, so 2 goes into 4
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.1
→1 2 =1 2 =1 × 2 2 × 2 2 4 - Subtract the whole numbers. The fraction part of the first number is big enough, so we can subtract the wholes and the fractions separately.4 − 1 = 3
- Subtract the fractions. Subtract the numerators. The denominator stays the same.
−3 4 =2 4 1 4 - Write the answer. 4
− 13 4 = 31 2 1 4
Check. Add back: 3
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 5, so we can subtract straight away.
- The first fraction part (1) is smaller than the second (3), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 5 fifths, so the numbers become fractions over 5.3
=1 5 =3 × 5 + 1 5 16 5
1 =3 5 =1 × 5 + 3 5 8 5 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−16 5 =8 5 =16 − 8 5 8 5 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 8 ÷ 5.8 5 = 18 5 3 5 - Write the answer. 3
− 11 5 = 13 5 3 5
Check. Add back: 1
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 4, so we can subtract straight away.
- The first fraction part (1) is smaller than the second (3), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 4 quarters, so the numbers become fractions over 4.4
=1 4 =4 × 4 + 1 4 17 4
2 =3 4 =2 × 4 + 3 4 11 4 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−17 4 =11 4 =17 − 11 4 6 4 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 6 ÷ 4.6 4 = 16 4 2 4 - Simplify the fraction part. 2 and 4 can both be divided by 2.
=2 4 =2 ÷ 2 4 ÷ 2 1 2
So the answer is 1 .1 2 - Write the answer. 4
− 21 4 = 13 4 1 2
Check. Add back: 1
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 8, so we can subtract straight away.
- The first fraction part (1) is smaller than the second (5), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 8 eighths, so the numbers become fractions over 8.2
=1 8 =2 × 8 + 1 8 17 8
1 =5 8 =1 × 8 + 5 8 13 8 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−17 8 =13 8 =17 − 13 8 4 8 - Simplify the fraction part. 4 and 8 can both be divided by 4.
=4 8 =4 ÷ 4 8 ÷ 4 1 2 - Write the answer. 2
− 11 8 =5 8 1 2
Check. Add back:
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 10, so we can subtract straight away.
- The first fraction part (1) is smaller than the second (7), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 10 tenths, so the numbers become fractions over 10.6
=1 10 =6 × 10 + 1 10 61 10
3 =7 10 =3 × 10 + 7 10 37 10 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−61 10 =37 10 =61 − 37 10 24 10 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 24 ÷ 10.24 10 = 224 10 4 10 - Simplify the fraction part. 4 and 10 can both be divided by 2.
=4 10 =4 ÷ 2 10 ÷ 2 2 5
So the answer is 2 .2 5 - Write the answer. 6
− 31 10 = 27 10 2 5
Check. Add back: 2
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- The first fraction part (0) is smaller than the second (3), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 8 eighths, so the numbers become fractions over 8.4
=0 8 =4 × 8 + 0 8 32 8
1 =3 8 =1 × 8 + 3 8 11 8 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−32 8 =11 8 =32 − 11 8 21 8 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 21 ÷ 8.21 8 = 221 8 5 8 - Write the answer. 4 − 1
= 23 8 5 8
Check. Add back: 2
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- The first fraction part (0) is smaller than the second (1), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 4 quarters, so the numbers become fractions over 4.5
=0 4 =5 × 4 + 0 4 20 4
2 =1 4 =2 × 4 + 1 4 9 4 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−20 4 =9 4 =20 − 9 4 11 4 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 11 ÷ 4.11 4 = 211 4 3 4 - Write the answer. 5 − 2
= 21 4 3 4
Check. Add back: 2
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- The first fraction part (0) is smaller than the second (2), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 5 fifths, so the numbers become fractions over 5.3
=0 5 =3 × 5 + 0 5 15 5
1 =2 5 =1 × 5 + 2 5 7 5 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−15 5 =7 5 =15 − 7 5 8 5 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 8 ÷ 5.8 5 = 18 5 3 5 - Write the answer. 3 − 1
= 12 5 3 5
Check. Add back: 1
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- The first fraction part (0) is smaller than the second (7), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 10 tenths, so the numbers become fractions over 10.6
=0 10 =6 × 10 + 0 10 60 10
2 =7 10 =2 × 10 + 7 10 27 10 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−60 10 =27 10 =60 − 27 10 33 10 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 33 ÷ 10.33 10 = 333 10 3 10 - Write the answer. 6 − 2
= 37 10 3 10
Check. Add back: 3
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 4, so 4 will do.4 ÷ 2 = 2, so 2 goes into 4
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.2
→1 2 =1 2 =1 × 2 2 × 2 2 4 - Add the whole numbers. Add the wholes first, then deal with the fractions.2 + 1 = 3
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+2 4 =3 4 =2 + 3 4 5 4 - The fraction part is 1 or more, so change it to a whole number and a fraction.
means 5 ÷ 4.5 4 = 15 4 1 4
3 + 1 = 41 4 1 4 - Write the answer. 2
+ 11 2 = 43 4 1 4
Check. Take away: 4
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 4, so 4 will do.4 ÷ 2 = 2, so 2 goes into 4
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.1
→1 2 =1 2 =1 × 2 2 × 2 2 4 - Add the whole numbers. Add the wholes first, then deal with the fractions.1 + 2 = 3
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+2 4 =3 4 =2 + 3 4 5 4 - The fraction part is 1 or more, so change it to a whole number and a fraction.
means 5 ÷ 4.5 4 = 15 4 1 4
3 + 1 = 41 4 1 4 - Write the answer. 1
+ 21 2 = 43 4 1 4
Check. Take away: 4
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 4, so 4 will do.4 ÷ 2 = 2, so 2 goes into 4
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.1
→1 2 =1 2 =1 × 2 2 × 2 2 4 - Subtract the whole numbers. The fraction part of the first number is big enough, so we can subtract the wholes and the fractions separately.2 − 1 = 1
- Subtract the fractions. Subtract the numerators. The denominator stays the same.
−3 4 =2 4 1 4 - Write the answer. 2
− 13 4 = 11 2 1 4
Check. Add back: 1
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Add the two pieces that are cut off, then take the total away from the whole plank.
- Draw a bar model. The plank is 5 m. The two cut pieces and the piece left make the whole.
- Find the total length of the two pieces. Add the two lengths.1
+ 23 4 =1 2 +7 4 =10 4 = 417 4 m1 4 - Take the total from 5 m. What is left is the missing piece. Write 5 as an improper fraction.5 − 4
=1 4 −20 4 =17 4 3 4 - Write the answer.
m is left3 4
Check. 4
Watch out. This is a two-step problem. The answer is not the total of the pieces.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Use the inverse (opposite) operation to find the missing number.
- Choose the operation. We know 2
+ ? = 43 4 . The missing number is what is left when we take 21 4 from 43 4 .1 4 4 − 21 4 = 13 4 1 2 - Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 4, so we can subtract straight away.
- The first fraction part (1) is smaller than the second (3), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 4 quarters, so the numbers become fractions over 4.4
=1 4 =4 × 4 + 1 4 17 4
2 =3 4 =2 × 4 + 3 4 11 4 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−17 4 =11 4 =17 − 11 4 6 4 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 6 ÷ 4.6 4 = 16 4 2 4 - Simplify the fraction part. 2 and 4 can both be divided by 2.
=2 4 =2 ÷ 2 4 ÷ 2 1 2
So the answer is 1 .1 2 - Write the answer. 4
− 21 4 = 13 4 1 2
Check. Put it back in: 2
Watch out. The missing number is not always the first or second number. Use the opposite operation.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Use the inverse (opposite) operation to find the missing number.
- Choose the operation. We know ? − 1
= 21 5 . To undo the subtraction, add 13 5 to 21 5 .3 5 2 + 13 5 = 31 5 4 5 - Check the denominators. To add fractions, the parts must be the same size.Both denominators are 5, so we can add straight away.
- Add the whole numbers. Add the wholes first, then deal with the fractions.2 + 1 = 3
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+3 5 =1 5 =3 + 1 5 4 5 - Write the answer. 2
+ 13 5 = 31 5 4 5
Check. Put it back in: 3
Watch out. The missing number is not always the first or second number. Use the opposite operation.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Work the question out yourself first. Then compare your working with the working in the question and find where it goes wrong.
- Work it out correctly. We need the right answer to compare with.3
=1 5 and 116 5 =3 5 .8 5 −16 5 =8 5 = 18 5 .3 5 - Find the mistake. Ravi did 3 − 1 = 2 for the wholes, and then took the smaller fraction from the bigger one: 3 fifths − 1 fifth = 2 fifths. But the first number only has 1 fifth, and we need to take away 3 fifths. He has to change to improper fractions.Ravi wrote 3
− 11 5 = 23 5 .2 5 - Write the correct answer. The correct answer is 1
.3 5
Check. 1
Watch out. If the fraction you take away is bigger, change to improper fractions.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Work the question out yourself first. Then compare your working with the working in the question and find where it goes wrong.
- Work it out correctly. We need the right answer to compare with.2
+ 13 4 : 2 + 1 = 3 and3 4 +3 4 =3 4 = 16 4 . 3 + 11 2 = 41 2 .1 2 - Find the mistake. Mia added correctly, but she stopped too soon. The fraction part
is bigger than 1, so it holds another whole.6 4 Mia wrote 2 + 13 4 = 33 4 .6 4 - Write the correct answer. The correct answer is 4
.1 2
Check. 3
Watch out. The fraction part of a mixed number must always be less than 1.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Add all four sides. Add the length and the width, then double the total.
- Find the total of the two side lengths. A rectangle has two long sides and two short sides. Half the perimeter is one long side plus one short side.2
+ 11 2 = 23 4 + 12 4 = 3 +3 4 = 45 4 1 4 - Double it. The perimeter goes all the way round, so there are two of these totals.4
+ 41 4 = 8 +1 4 = 8 +2 4 = 81 2 1 2 - Write the answer with the unit. The sides are in centimetres.The perimeter is 8
cm.1 2
Check. 2 × 2
Watch out. Perimeter is the distance all the way round: four sides, not two.
Multiplying fractions by whole numbers and fractions of amounts
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
Multiplying by a whole number is repeated addition. 3 ×
For a mixed number, multiply the whole part and the fraction part separately, then add. 4 × 1
Fractions of amounts (a reminder). To find
Key ideas
- Fraction × whole number: multiply the numerator, keep the denominator. 3 ×
=2 5 . Then write it as a mixed number and simplify.6 5 - Mixed number × whole number: multiply the whole part and the fraction part separately, then add (or change to an improper fraction first).
- Fraction of an amount: ÷ by the denominator, × by the numerator.
- Finding the whole: if
of a number is 18, one fifth is 18 ÷ 3 = 6, so the whole is 5 × 6 = 30.3 5
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 3 ×
as 3 lots of2 5 . Multiplying by a whole number is repeated addition.2 5 +2 5 +2 5 2 5 - Multiply the numerator by 3. Keep the denominator. We are counting fifths. 3 lots of 2 fifths is 6 fifths.3 ×
=2 5 =3 × 2 5 6 5 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 6 ÷ 5.6 5 = 16 5 1 5 - Write the answer. 3 ×
= 12 5 1 5
Check. Divide back: 1
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 4 ×
as 4 lots of3 8 . Multiplying by a whole number is repeated addition.3 8 +3 8 +3 8 +3 8 3 8 - Multiply the numerator by 4. Keep the denominator. We are counting eighths. 4 lots of 3 eighths is 12 eighths.4 ×
=3 8 =4 × 3 8 12 8 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 12 ÷ 8.12 8 = 112 8 4 8 - Simplify the fraction part. 4 and 8 can both be divided by 4.
=4 8 =4 ÷ 4 8 ÷ 4 1 2
So the answer is 1 .1 2 - Write the answer. 4 ×
= 13 8 1 2
Check. Divide back: 1
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 6 ×
as 6 lots of1 3 . Multiplying by a whole number is repeated addition.1 3 +1 3 +1 3 +1 3 +1 3 +1 3 1 3 - Multiply the numerator by 6. Keep the denominator. We are counting thirds. 6 lots of 1 thirds is 6 thirds.6 ×
=1 3 =6 × 1 3 6 3 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 6 ÷ 3.6 3 = 26 3 - Write the answer. 6 ×
= 21 3
Check. Divide back: 2 ÷ 6 =
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 5 ×
as 5 lots of3 4 . Multiplying by a whole number is repeated addition.3 4 +3 4 +3 4 +3 4 +3 4 3 4 - Multiply the numerator by 5. Keep the denominator. We are counting quarters. 5 lots of 3 quarters is 15 quarters.5 ×
=3 4 =5 × 3 4 15 4 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 15 ÷ 4.15 4 = 315 4 3 4 - Write the answer. 5 ×
= 33 4 3 4
Check. Divide back: 3
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the whole part and the fraction part separately, then add the answers. (Or change to an improper fraction first.)
- Split the mixed number into its whole part and its fraction part. We multiply each part by the whole number, then add the answers (the distributive law).1
= 1 +1 2 1 2 - Multiply the whole part. The whole numbers multiply as usual.4 × 1 = 4
- Multiply the fraction part. Multiply the numerator by 4 and keep the denominator.4 ×
=1 2 = 24 2 - Add the two answers. Put the whole parts and the fraction parts back together.4 + 2 = 6
- Write the answer. 4 × 1
= 61 2
Check. Other way: 1
Watch out. Do not forget to multiply the whole part as well as the fraction part.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the whole part and the fraction part separately, then add the answers. (Or change to an improper fraction first.)
- Split the mixed number into its whole part and its fraction part. We multiply each part by the whole number, then add the answers (the distributive law).2
= 2 +1 4 1 4 - Multiply the whole part. The whole numbers multiply as usual.3 × 2 = 6
- Multiply the fraction part. Multiply the numerator by 3 and keep the denominator.3 ×
=1 4 3 4 - Add the two answers. Put the whole parts and the fraction parts back together.6 +
= 63 4 3 4 - Write the answer. 3 × 2
= 61 4 3 4
Check. Other way: 2
Watch out. Do not forget to multiply the whole part as well as the fraction part.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 4 tells us to cut the amount into 4 equal parts. One part is
of the amount.1 4 36 ÷ 4 = 9 - Multiply by the numerator. The numerator 3 tells us how many of those parts we want.3 × 9 = 27
- Write the answer.
of 36 = 273 4
Check. Other way: 3 × 36 = 108, then ÷ 4 = 27. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 8 tells us to cut the amount into 8 equal parts. One part is
of the amount.1 8 £48 ÷ 8 = £6 - Multiply by the numerator. The numerator 5 tells us how many of those parts we want.5 × £6 = £30
- Write the answer.
of £48 = £305 8
Check. Other way: 5 × £48 = £240, then ÷ 8 = £30. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. Use a bar model. The known part tells us the value of one small part. Then multiply to find the whole.
- 3 parts are worth 18. Find the value of one part. The top number 3 is how many parts make 18, so divide by 3.18 ÷ 3 = 6
- Find the whole. The whole is 5 parts. The bottom number 5 is how many equal parts there are altogether.5 × 6 = 30
- Check with the fraction. Take the fraction of the whole you found.
of 30 = 6 × 3 = 18 ✓3 5
Check.
Watch out. Divide by the numerator first to find one part, then multiply by the denominator.
Watch out
Multiply the numerator only. 3 ×Exercise 6G Multiplying by whole numbers and fractions of amounts
Non-calculatorKey words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 3 ×
as 3 lots of2 5 . Multiplying by a whole number is repeated addition.2 5 +2 5 +2 5 2 5 - Multiply the numerator by 3. Keep the denominator. We are counting fifths. 3 lots of 2 fifths is 6 fifths.3 ×
=2 5 =3 × 2 5 6 5 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 6 ÷ 5.6 5 = 16 5 1 5 - Write the answer. 3 ×
= 12 5 1 5
Check. Divide back: 1
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 3 ×
as 3 lots of1 4 . Multiplying by a whole number is repeated addition.1 4 +1 4 +1 4 1 4 - Multiply the numerator by 3. Keep the denominator. We are counting quarters. 3 lots of 1 quarters is 3 quarters.3 ×
=1 4 =3 × 1 4 3 4 - Write the answer. It is already a proper fraction in its simplest form.
3 4
Check. Divide back:
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 4 ×
as 4 lots of1 6 . Multiplying by a whole number is repeated addition.1 6 +1 6 +1 6 +1 6 1 6 - Multiply the numerator by 4. Keep the denominator. We are counting sixths. 4 lots of 1 sixths is 4 sixths.4 ×
=1 6 =4 × 1 6 4 6 - Simplify the fraction part. 4 and 6 can both be divided by 2.
=4 6 =4 ÷ 2 6 ÷ 2 2 3 - Write the answer. 4 ×
=1 6 2 3
Check. Divide back:
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 5 ×
as 5 lots of1 3 . Multiplying by a whole number is repeated addition.1 3 +1 3 +1 3 +1 3 +1 3 1 3 - Multiply the numerator by 5. Keep the denominator. We are counting thirds. 5 lots of 1 thirds is 5 thirds.5 ×
=1 3 =5 × 1 3 5 3 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 5 ÷ 3.5 3 = 15 3 2 3 - Write the answer. 5 ×
= 11 3 2 3
Check. Divide back: 1
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 6 ×
as 6 lots of1 8 . Multiplying by a whole number is repeated addition.1 8 +1 8 +1 8 +1 8 +1 8 +1 8 1 8 - Multiply the numerator by 6. Keep the denominator. We are counting eighths. 6 lots of 1 eighths is 6 eighths.6 ×
=1 8 =6 × 1 8 6 8 - Simplify the fraction part. 6 and 8 can both be divided by 2.
=6 8 =6 ÷ 2 8 ÷ 2 3 4 - Write the answer. 6 ×
=1 8 3 4
Check. Divide back:
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 4 ×
as 4 lots of3 7 . Multiplying by a whole number is repeated addition.3 7 +3 7 +3 7 +3 7 3 7 - Multiply the numerator by 4. Keep the denominator. We are counting sevenths. 4 lots of 3 sevenths is 12 sevenths.4 ×
=3 7 =4 × 3 7 12 7 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 12 ÷ 7.12 7 = 112 7 5 7 - Write the answer. 4 ×
= 13 7 5 7
Check. Divide back: 1
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 5 ×
as 5 lots of2 3 . Multiplying by a whole number is repeated addition.2 3 +2 3 +2 3 +2 3 +2 3 2 3 - Multiply the numerator by 5. Keep the denominator. We are counting thirds. 5 lots of 2 thirds is 10 thirds.5 ×
=2 3 =5 × 2 3 10 3 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 10 ÷ 3.10 3 = 310 3 1 3 - Write the answer. 5 ×
= 32 3 1 3
Check. Divide back: 3
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 3 ×
as 3 lots of5 8 . Multiplying by a whole number is repeated addition.5 8 +5 8 +5 8 5 8 - Multiply the numerator by 3. Keep the denominator. We are counting eighths. 3 lots of 5 eighths is 15 eighths.3 ×
=5 8 =3 × 5 8 15 8 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 15 ÷ 8.15 8 = 115 8 7 8 - Write the answer. 3 ×
= 15 8 7 8
Check. Divide back: 1
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 6 ×
as 6 lots of3 10 . Multiplying by a whole number is repeated addition.3 10 +3 10 +3 10 +3 10 +3 10 +3 10 3 10 - Multiply the numerator by 6. Keep the denominator. We are counting tenths. 6 lots of 3 tenths is 18 tenths.6 ×
=3 10 =6 × 3 10 18 10 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 18 ÷ 10.18 10 = 118 10 8 10 - Simplify the fraction part. 8 and 10 can both be divided by 2.
=8 10 =8 ÷ 2 10 ÷ 2 4 5
So the answer is 1 .4 5 - Write the answer. 6 ×
= 13 10 4 5
Check. Divide back: 1
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 4 ×
as 4 lots of3 8 . Multiplying by a whole number is repeated addition.3 8 +3 8 +3 8 +3 8 3 8 - Multiply the numerator by 4. Keep the denominator. We are counting eighths. 4 lots of 3 eighths is 12 eighths.4 ×
=3 8 =4 × 3 8 12 8 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 12 ÷ 8.12 8 = 112 8 4 8 - Simplify the fraction part. 4 and 8 can both be divided by 4.
=4 8 =4 ÷ 4 8 ÷ 4 1 2
So the answer is 1 .1 2 - Write the answer. 4 ×
= 13 8 1 2
Check. Divide back: 1
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 6 ×
as 6 lots of5 12 . Multiplying by a whole number is repeated addition.5 12 +5 12 +5 12 +5 12 +5 12 +5 12 5 12 - Multiply the numerator by 6. Keep the denominator. We are counting twelfths. 6 lots of 5 twelfths is 30 twelfths.6 ×
=5 12 =6 × 5 12 30 12 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 30 ÷ 12.30 12 = 230 12 6 12 - Simplify the fraction part. 6 and 12 can both be divided by 6.
=6 12 =6 ÷ 6 12 ÷ 6 1 2
So the answer is 2 .1 2 - Write the answer. 6 ×
= 25 12 1 2
Check. Divide back: 2
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 6 ×
as 6 lots of7 10 . Multiplying by a whole number is repeated addition.7 10 +7 10 +7 10 +7 10 +7 10 +7 10 7 10 - Multiply the numerator by 6. Keep the denominator. We are counting tenths. 6 lots of 7 tenths is 42 tenths.6 ×
=7 10 =6 × 7 10 42 10 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 42 ÷ 10.42 10 = 442 10 2 10 - Simplify the fraction part. 2 and 10 can both be divided by 2.
=2 10 =2 ÷ 2 10 ÷ 2 1 5
So the answer is 4 .1 5 - Write the answer. 6 ×
= 47 10 1 5
Check. Divide back: 4
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 8 ×
as 8 lots of3 4 . Multiplying by a whole number is repeated addition.3 4 8 lots of3 4 - Multiply the numerator by 8. Keep the denominator. We are counting quarters. 8 lots of 3 quarters is 24 quarters.8 ×
=3 4 =8 × 3 4 24 4 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 24 ÷ 4.24 4 = 624 4 - Write the answer. 8 ×
= 63 4
Check. Divide back: 6 ÷ 8 =
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the whole part and the fraction part separately, then add the answers. (Or change to an improper fraction first.)
- Split the mixed number into its whole part and its fraction part. We multiply each part by the whole number, then add the answers (the distributive law).1
= 1 +1 4 1 4 - Multiply the whole part. The whole numbers multiply as usual.2 × 1 = 2
- Multiply the fraction part. Multiply the numerator by 2 and keep the denominator.2 ×
=1 4 2 4 - Add the two answers. Put the whole parts and the fraction parts back together.2 +
= 21 2 1 2 - Write the answer. 2 × 1
= 21 4 1 2
Check. Other way: 1
Watch out. Do not forget to multiply the whole part as well as the fraction part.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the whole part and the fraction part separately, then add the answers. (Or change to an improper fraction first.)
- Split the mixed number into its whole part and its fraction part. We multiply each part by the whole number, then add the answers (the distributive law).1
= 1 +2 3 2 3 - Multiply the whole part. The whole numbers multiply as usual.3 × 1 = 3
- Multiply the fraction part. Multiply the numerator by 3 and keep the denominator.3 ×
=2 3 = 26 3 - Add the two answers. Put the whole parts and the fraction parts back together.3 + 2 = 5
- Write the answer. 3 × 1
= 52 3
Check. Other way: 1
Watch out. Do not forget to multiply the whole part as well as the fraction part.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the whole part and the fraction part separately, then add the answers. (Or change to an improper fraction first.)
- Split the mixed number into its whole part and its fraction part. We multiply each part by the whole number, then add the answers (the distributive law).2
= 2 +1 2 1 2 - Multiply the whole part. The whole numbers multiply as usual.4 × 2 = 8
- Multiply the fraction part. Multiply the numerator by 4 and keep the denominator.4 ×
=1 2 = 24 2 - Add the two answers. Put the whole parts and the fraction parts back together.8 + 2 = 10
- Write the answer. 4 × 2
= 101 2
Check. Other way: 2
Watch out. Do not forget to multiply the whole part as well as the fraction part.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the whole part and the fraction part separately, then add the answers. (Or change to an improper fraction first.)
- Split the mixed number into its whole part and its fraction part. We multiply each part by the whole number, then add the answers (the distributive law).1
= 1 +3 10 3 10 - Multiply the whole part. The whole numbers multiply as usual.5 × 1 = 5
- Multiply the fraction part. Multiply the numerator by 5 and keep the denominator.5 ×
=3 10 = 115 10 1 2 - Add the two answers. Put the whole parts and the fraction parts back together.5 + 1
= 61 2 1 2 - Write the answer. 5 × 1
= 63 10 1 2
Check. Other way: 1
Watch out. Do not forget to multiply the whole part as well as the fraction part.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Undo the multiplication with division. To divide a fraction by 3, divide the numerator by 3 (when it goes in exactly).
- Write what we know. 3 lots of the missing fraction make
.9 10 3 × ? =9 10 - Divide the numerator by 3. 9 ÷ 3 = 3. The denominator stays 10.
÷ 3 =9 10 3 10 - Write the answer.
3 10
Check. 3 ×
Watch out. The denominator does not change. Only the numerator is divided.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Undo the multiplication with division. To divide a fraction by 3, divide the numerator by 3 (when it goes in exactly).
- Write what we know. 3 lots of the missing fraction make
.6 5 3 × ? =6 5 - Divide the numerator by 3. 6 ÷ 3 = 2. The denominator stays 5.
÷ 3 =6 5 2 5 - Write the answer.
2 5
Check. 3 ×
Watch out. The denominator does not change. Only the numerator is divided.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Undo the multiplication with division. To divide a fraction by 5, divide the numerator by 5 (when it goes in exactly).
- Write what we know. 5 lots of the missing fraction make
.15 8 5 × ? =15 8 - Divide the numerator by 5. 15 ÷ 5 = 3. The denominator stays 8.
÷ 5 =15 8 3 8 - Write the answer.
3 8
Check. 5 ×
Watch out. The denominator does not change. Only the numerator is divided.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 4 tells us to cut the amount into 4 equal parts. One part is
of the amount.1 4 36 ÷ 4 = 9 - Multiply by the numerator. The numerator 3 tells us how many of those parts we want.3 × 9 = 27
- Write the answer.
of 36 = 273 4
Check. Other way: 3 × 36 = 108, then ÷ 4 = 27. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 5 tells us to cut the amount into 5 equal parts. One part is
of the amount.1 5 45 ÷ 5 = 9 - Multiply by the numerator. The numerator 2 tells us how many of those parts we want.2 × 9 = 18
- Write the answer.
of 45 = 182 5
Check. Other way: 2 × 45 = 90, then ÷ 5 = 18. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 8 tells us to cut the amount into 8 equal parts. One part is
of the amount.1 8 48 ÷ 8 = 6 - Multiply by the numerator. The numerator 5 tells us how many of those parts we want.5 × 6 = 30
- Write the answer.
of 48 = 305 8
Check. Other way: 5 × 48 = 240, then ÷ 8 = 30. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 10 tells us to cut the amount into 10 equal parts. One part is
of the amount.1 10 90 ÷ 10 = 9 - Multiply by the numerator. The numerator 7 tells us how many of those parts we want.7 × 9 = 63
- Write the answer.
of 90 = 637 10
Check. Other way: 7 × 90 = 630, then ÷ 10 = 63. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 3 tells us to cut the amount into 3 equal parts. One part is
of the amount.1 3 27 ÷ 3 = 9 - Multiply by the numerator. The numerator 2 tells us how many of those parts we want.2 × 9 = 18
- Write the answer.
of 27 = 182 3
Check. Other way: 2 × 27 = 54, then ÷ 3 = 18. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 6 tells us to cut the amount into 6 equal parts. One part is
of the amount.1 6 42 ÷ 6 = 7 - Multiply by the numerator. The numerator 5 tells us how many of those parts we want.5 × 7 = 35
- Write the answer.
of 42 = 355 6
Check. Other way: 5 × 42 = 210, then ÷ 6 = 35. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 5 tells us to cut the amount into 5 equal parts. One part is
of the amount.1 5 £35 ÷ 5 = £7 - Multiply by the numerator. The numerator 2 tells us how many of those parts we want.2 × £7 = £14
- Write the answer.
of £35 = £142 5
Check. Other way: 2 × £35 = £70, then ÷ 5 = £14. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 8 tells us to cut the amount into 8 equal parts. One part is
of the amount.1 8 64 kg ÷ 8 = 8 kg - Multiply by the numerator. The numerator 3 tells us how many of those parts we want.3 × 8 kg = 24 kg
- Write the answer.
of 64 kg = 24 kg3 8
Check. Other way: 3 × 64 kg = 192 kg, then ÷ 8 = 24 kg. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 12 tells us to cut the amount into 12 equal parts. One part is
of the amount.1 12 60 minutes ÷ 12 = 5 minutes - Multiply by the numerator. The numerator 7 tells us how many of those parts we want.7 × 5 minutes = 35 minutes
- Write the answer.
of 60 minutes = 35 minutes7 12
Check. Other way: 7 × 60 minutes = 420 minutes, then ÷ 12 = 35 minutes. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 10 tells us to cut the amount into 10 equal parts. One part is
of the amount.1 10 250 ml ÷ 10 = 25 ml - Multiply by the numerator. The numerator 3 tells us how many of those parts we want.3 × 25 ml = 75 ml
- Write the answer.
of 250 ml = 75 ml3 10
Check. Other way: 3 × 250 ml = 750 ml, then ÷ 10 = 75 ml. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 5 ×
as 5 lots of3 4 . Multiplying by a whole number is repeated addition.3 4 +3 4 +3 4 +3 4 +3 4 3 4 - Multiply the numerator by 5. Keep the denominator. We are counting quarters. 5 lots of 3 quarters is 15 quarters.5 ×
=3 4 =5 × 3 4 15 4 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 15 ÷ 4.15 4 = 315 4 3 4 - Write the answer. 5 ×
= 33 4 3 4
Check. Divide back: 3
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 4 ×
as 4 lots of3 10 . Multiplying by a whole number is repeated addition.3 10 +3 10 +3 10 +3 10 3 10 - Multiply the numerator by 4. Keep the denominator. We are counting tenths. 4 lots of 3 tenths is 12 tenths.4 ×
=3 10 =4 × 3 10 12 10 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 12 ÷ 10.12 10 = 112 10 2 10 - Simplify the fraction part. 2 and 10 can both be divided by 2.
=2 10 =2 ÷ 2 10 ÷ 2 1 5
So the answer is 1 .1 5 - Write the answer. 4 ×
= 13 10 1 5
Check. Divide back: 1
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the whole part and the fraction part separately, then add the answers. (Or change to an improper fraction first.)
- Split the mixed number into its whole part and its fraction part. We multiply each part by the whole number, then add the answers (the distributive law).2
= 2 +1 2 1 2 - Multiply the whole part. The whole numbers multiply as usual.4 × 2 = 8
- Multiply the fraction part. Multiply the numerator by 4 and keep the denominator.4 ×
=1 2 = 24 2 - Add the two answers. Put the whole parts and the fraction parts back together.8 + 2 = 10
- Write the answer. 4 × 2
= 101 2
Check. Other way: 2
Watch out. Do not forget to multiply the whole part as well as the fraction part.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the whole part and the fraction part separately, then add the answers. (Or change to an improper fraction first.)
- Split the mixed number into its whole part and its fraction part. We multiply each part by the whole number, then add the answers (the distributive law).1
= 1 +1 3 1 3 - Multiply the whole part. The whole numbers multiply as usual.3 × 1 = 3
- Multiply the fraction part. Multiply the numerator by 3 and keep the denominator.3 ×
=1 3 = 13 3 - Add the two answers. Put the whole parts and the fraction parts back together.3 + 1 = 4
- Write the answer. 3 × 1
= 41 3
Check. Other way: 1
Watch out. Do not forget to multiply the whole part as well as the fraction part.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Work the question out yourself first. Then compare your working with the working in the question and find where it goes wrong.
- Work it out correctly. We need the right answer to compare with.3 ×
=2 5 = 16 5 1 5 - Find the mistake. Tom multiplied the numerator by 3 and the denominator by 3. But the denominator says what size the parts are, and they are still fifths.Tom wrote 3 ×
=2 5 .6 15 - Write the correct answer. The correct answer is 1
.1 5
Check.
Watch out. Multiply the numerator. Keep the denominator.
Key words. Always means true every time. Never means false every time. Sometimes means true for some numbers and false for others.
Method. Test the statement with some numbers. If it is always true, never true, or true for some numbers only, that gives the answer.
- Try some examples. Testing numbers helps us see if the statement is true every time.3 ×
=1 4 , bigger than3 4 1 4
2 × = 12 3 , bigger than1 3 2 3
5 × =1 10 , bigger than1 2 1 10 - Decide: always, sometimes or never? Multiplying by a whole number bigger than 1 means adding the fraction to itself, so the total is bigger.Always
Check. All the answers are bigger. ✓
Watch out. To show a statement is “always” true you need a reason. A few examples are not enough to prove it, but one counter-example shows it is not always true.
Key words. Always means true every time. Never means false every time. Sometimes means true for some numbers and false for others.
Method. Test the statement with some numbers. If it is always true, never true, or true for some numbers only, that gives the answer.
- Try some examples. Testing numbers helps us see if the statement is true every time.3 ×
=1 6 , which is less than 1.1 2 - Look for an example that does not work. One example that breaks the rule is a counter-example.3 ×
= 2, which is more than 1.2 3 - Decide: always, sometimes or never? It depends on the fraction. A small fraction gives an answer less than 1, a big fraction gives more than 1.Sometimes
Check. We found one of each. ✓
Watch out. To show a statement is “always” true you need a reason. A few examples are not enough to prove it, but one counter-example shows it is not always true.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Work out the value of each one in its simplest form. Three will be the same. The odd one out is the one that is different.
- Write each one in its simplest form. Then equal values are easy to spot.3 ×
= 22 3
6 × = 21 3
4 × = 21 2
2 × 1 = 21 3 2 3 - Find the one that is different. The other three have the same value.2 × 1
is the odd one out.1 3
Check. Check the three that match once more. ✓
Watch out. Compare values, not the look of the numbers.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Use the opposite operation. The answer 4½ is shared into 6 equal parts, so divide by 6.
- Change 4½ to an improper fraction. 4
= 4 × 2 + 1 = 9 halves.1 2 4 =1 2 9 2 - Divide by 6. Dividing a fraction by 6 makes each part 6 times smaller. Write it as a division of 9 by 12 parts.
÷ 6 =9 2 =9 2 × 6 9 12 - Simplify. 9 and 12 can both be divided by 3.
=9 12 3 4
Check. 6 ×
Watch out. Work backwards, using the inverse operation.
Exercise 6H Fraction problems
Non-calculatorKey words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. Use a bar model. The known part tells us the value of one small part. Then multiply to find the whole.
- 3 parts are worth 18. Find the value of one part. The top number 3 is how many parts make 18, so divide by 3.18 ÷ 3 = 6
- Find the whole. The whole is 5 parts. The bottom number 5 is how many equal parts there are altogether.5 × 6 = 30
- Check with the fraction. Take the fraction of the whole you found.
of 30 = 6 × 3 = 18 ✓3 5
Check.
Watch out. Divide by the numerator first to find one part, then multiply by the denominator.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. Use a bar model. The known part tells us the value of one small part. Then multiply to find the whole.
- 2 parts are worth £24. Find the value of one part. The top number 2 is how many parts make £24, so divide by 2.£24 ÷ 2 = £12
- Find the whole. The whole is 3 parts. The bottom number 3 is how many equal parts there are altogether.3 × £12 = £36
- Check with the fraction. Take the fraction of the whole you found.
of £36 = £12 × 2 = £24 ✓2 3
Check.
Watch out. Divide by the numerator first to find one part, then multiply by the denominator.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. Find how many walk and how many cycle. Then subtract both from the total.
- Find the fraction that walk.
of 40.3 8 40 ÷ 8 = 5, then 3 × 5 = 15 walk - Find the fraction that cycle.
of 40.1 4 40 ÷ 4 = 10 cycle - Take both from 40. The rest come by bus.15 + 10 = 25, so 40 − 25 = 15
- Check with fractions. Add the two fractions and take them from 1.
+3 8 =2 8 , and 1 −5 8 =5 8 , and3 8 of 40 = 15 ✓3 8
Check. 15 + 15 + 10 = 40. ✓
Watch out. The question asks about the bus, not the walkers.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. Find the number of squares each child eats, then take them from 12.
- Find the squares Ravi eats.
of 12.1 4 12 ÷ 4 = 3 - Find the squares Priya eats.
of 12.1 3 12 ÷ 3 = 4 - Add them and take from 12. The rest of the bar is left.3 + 4 = 7, so 12 − 7 = 5
Check.
Watch out. Find squares, not fractions, in the last step.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. Work out both amounts, then compare them.
- Find
of 20. 20 ÷ 4 = 5, then 3 × 5.3 4 3 × 5 = 15 - Find
of 24. 24 ÷ 3 = 8, then 2 × 8.2 3 2 × 8 = 16 - Compare. 15 < 16
Check. 15 < 16, so
Watch out. Compare the amounts, not the fractions, because the wholes are different.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=2 5 =2 × 2 5 × 2 4 10 - Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+3 10 =4 10 =3 + 4 10 7 10 - Write the answer.
+3 10 =2 5 7 10
Check. Take away:
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- The first fraction part (0) is smaller than the second (7), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 10 tenths, so the numbers become fractions over 10.1
=0 10 =1 × 10 + 0 10 10 10 =7 10 =0 × 10 + 7 10 7 10 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−10 10 =7 10 =10 − 7 10 3 10 - Write the answer. It is already in its simplest form.
3 10
Check. Add back:
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Change every fraction to eighths, then add the numerators.
- Change to eighths. 2, 4 and 8 all go into 8.
=1 2 ,4 8 =1 4 ,2 8 =1 8 1 8 - Add the numerators. The denominator stays 8.
+4 8 +2 8 =1 8 7 8 - Write the answer. It is already in its simplest form.
7 8
Check.
Watch out. Add the numerators only.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. Find the number of boys first. The rest are girls.
- Find the number of boys.
of 28.3 7 28 ÷ 7 = 4, then 3 × 4 = 12 boys - Find the number of girls. Girls are the rest of the class.28 − 12 = 16 girls
Check.
Watch out. The question asks for girls, not boys.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. Work out each amount spent, add them, then take the total from £60.
- Find the money spent on the book.
of £60.1 4 60 ÷ 4 = £15 - Find the money spent on trainers.
of £60.2 5 60 ÷ 5 = 12, then 2 × 12 = £24 - Find the total spent. Add the two amounts.15 + 24 = £39
- Find the money left. Subtract from the £60.60 − 39 = £21
Check.
Watch out. Do not forget the last step: she has money left over.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. Use a bar model. The known part tells us the value of one small part. Then multiply to find the whole.
- 3 parts are worth 36 litres. Find the value of one part. The top number 3 is how many parts make 36 litres, so divide by 3.36 litres ÷ 3 = 12 litres
- Find the whole. The whole is 4 parts. The bottom number 4 is how many equal parts there are altogether.4 × 12 litres = 48 litres
- Check with the fraction. Take the fraction of the whole you found.
of 48 litres = 12 litres × 3 = 36 litres ✓3 4
Check.
Watch out. Divide by the numerator first to find one part, then multiply by the denominator.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Work out both multiplications and compare the answers.
- Work out 3 × 2/5. Multiply the numerator by 3.3 ×
=2 5 6 5 - Work out 2 × 3/5. Multiply the numerator by 2.2 ×
=3 5 6 5 - Compare. Both multiply 2 and 3 to make 6 fifths.Both are
= 16 5 . They are equal.1 5
Check. Both are 6 lots of
Watch out. The order of a multiplication does not change the answer.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. Find the difference between one half and one third. That difference is worth 7.
- Draw a bar model. Half of the number and one third of the number are fractions of the same bar. Cut it into sixths.
- Find the difference between the two fractions. The difference is the part of the bar that is in the half but not in the third.
−1 2 =1 3 −3 6 =2 6 1 6 - Use the 7. The difference (
of the number) is 7, so one sixth is 7.1 6 1 sixth = 7 - Find the whole number. The number is 6 sixths.6 × 7 = 42
Check.
Watch out. A diagram showing the half and the third on the same bar helps.
Chapter summary
| Skill | Method |
|---|---|
| Equivalent fractions | Multiply or divide the top and the bottom by the SAME number: |
| Simplify | Divide the top and the bottom by a common factor (the HCF does it in one go). Simplest form: the only common factor is 1. |
| Compare and order | Same denominator: bigger numerator = bigger fraction. Otherwise change to a common denominator first. Write the original fractions in the answer. |
| Improper to mixed | Divide the top by the bottom: whole number = answer, new top = remainder. |
| Mixed to improper | Whole × bottom + top, over the same bottom: 2 |
| Fractions as division | The fraction line means divide: 3 ÷ 4 = |
| Add and subtract fractions | Same denominator: add or subtract the numerators and keep the denominator. Different: common denominator first. Simplify, and write answers over 1 as mixed numbers. |
| Mixed numbers | Add (or subtract) the wholes and the fractions. If the fraction part is 1 or more, carry a whole. If you cannot take the fraction away, change to improper fractions. |
| Fraction × whole number | Multiply the numerator and keep the denominator: 3 × |
| Fraction of an amount | Divide by the denominator, multiply by the numerator: |
| Reasoning | Spot the mistake by doing it yourself. Never add the denominators. “Prove it” needs working and a sentence. One counter-example breaks “always”. |
Can you…?
- I can find equivalent fractions by multiplying or dividing the top and the bottom by the same number, including tenths and hundredths.
- I can simplify a fraction by dividing by a common factor.
- I can compare and order fractions by changing them to a common denominator.
- I can change improper fractions to mixed numbers and mixed numbers to improper fractions.
- I can write a division as a fraction, such as 3 ÷ 4 =
.3 4 - I can add and subtract fractions with the same denominator and with denominators that are multiples of one another.
- I can add and subtract mixed numbers, including when I cross a whole number.
- I can multiply fractions and mixed numbers by whole numbers.
- I can find a fraction of an amount, and find the whole when I know a fraction of it.
- I can solve word problems with bar models and explain my reasoning.
Key terms
- Fraction
- A number that shows equal parts of a whole, such as
.3 8 - Numerator
- The top number of a fraction. It says how many parts we have.
- Denominator
- The bottom number of a fraction. It says how many equal parts the whole is cut into.
- Equivalent fractions
- Fractions that are worth the same amount, like
and1 2 .4 8 - Simplify
- To write a fraction with smaller numbers by dividing the top and the bottom by a common factor.
- Common factor
- A number that divides exactly into two or more numbers.
- Highest common factor (HCF)
- The biggest number that divides exactly into two numbers.
- Simplest form
- A fraction whose top and bottom have no common factor except 1.
- Common denominator
- A bottom number that the denominators of two or more fractions all go into.
- Unit fraction
- A fraction with a numerator of 1, such as
.1 5 - Improper fraction
- A fraction with a top number bigger than or equal to the bottom number, such as
.7 4 - Mixed number
- A whole number and a fraction together, such as 1
.3 4 - Fraction wall
- A picture of bricks that shows fractions of one whole, row by row.
- Ascending
- In order from the smallest to the largest.
- Descending
- In order from the largest to the smallest.
- Tenths and hundredths
- A tenth is one of 10 equal parts and a hundredth is one of 100 equal parts. 1 tenth = 10 hundredths.
- Counter-example
- One example that shows a statement is false.
- Bar model
- A drawing of bars that shows the parts and the whole of a problem.
Exercise 6Z Check-up (non-calculator)
Non-calculatorKey words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 4 by to get 20? This tells us how the fraction has been changed. We must do the same to the other number.4 × 5 = 20, so the multiplier is 5.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 5.3 × 5 = 15
- Write the equivalent fractions. Now both numbers are filled in.
=3 4 15 20
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. To simplify a fraction is to write it with smaller numbers. A common factor is a number that divides exactly into both the top and the bottom. The simplest form is when the only common factor is 1.
Method. Divide the top and the bottom by a common factor. The biggest common factor (the highest common factor, HCF) does it in one go.
- List the factors of 18 and of 30. A factor divides exactly into the number. We need the factors both numbers share (the common factors).Factors of 18: 1, 2, 3, 6, 9, 18
Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30
Common factors: 1, 2, 3, 6 - Pick the biggest common factor: 6. Divide the top and the bottom by 6. Dividing both numbers by the same number does not change the value of the fraction. It just writes it with smaller numbers.
=18 30 =18 ÷ 6 30 ÷ 6 3 5 - Check it is in its simplest form. If 3 and 5 still shared a factor, we could go on.The only common factor of 3 and 5 is 1, so
is the simplest form.3 5
Check. Multiply back: 3 × 6 = 18 and 5 × 6 = 30. ✓
Watch out. Divide the top and the bottom. Subtracting the same number from both changes the fraction.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Make the denominators the same. Then the fraction with the bigger numerator is the bigger fraction.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time, so the value does not change.
7 10 =3 5 =3 × 2 5 × 2 6 10 - Compare the top numbers. With the same bottom number, the fraction with the bigger top number is bigger.7 > 6
- Write the answer. Use the original fractions in your answer.
>7 10 3 5
Check. Look at the changed fractions again:
Watch out. A bigger denominator does not mean a bigger fraction: 1/8 is smaller than 1/4.
Key words. To order fractions is to put them in a line from the smallest to the largest (ascending) or from the largest to the smallest (descending). Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change every fraction to the same denominator. Then order the numerators.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 12, so 12 will do.12 ÷ 3 = 4, so 3 goes into 12
12 ÷ 6 = 2, so 6 goes into 12 - Change every fraction to the common denominator. Multiply the top and the bottom by the same number each time.
=2 3 =2 × 4 3 × 4 8 12 (already in twelfths)7 12 =5 6 =5 × 2 6 × 2 10 12 - Put the top numbers in order. With the same bottom number, the bigger the top number, the bigger the fraction. We want smallest to largest.7, 8, 10 (out of 12)
- Write the original fractions in that order. The answer uses the fractions from the question, not the changed ones.
,7 12 ,2 3 5 6
Check. Read the numerators again: 7, 8, 10 go up each time. ✓
Watch out. Write down the original fractions in your final answer.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. An improper fraction has more parts than one whole. Divide the top by the bottom to find how many whole ones it holds.
- Divide 23 by 6. The fraction line means divide. The answer tells us how many whole ones we can make.23 ÷ 6 = 3 remainder 5
- The whole number is 3. 3 lots of 6 sixths make 3 whole ones: 3 × 6 = 18.23 − 18 = 5 sixths are left over.
- Write the leftover parts as a fraction. The remainder is the numerator. The denominator stays 6.3 and
= 35 6 5 6
Check. Change back: 3 × 6 + 5 = 23 = 23. ✓
Watch out. The leftover (remainder) goes on top of the same denominator. Do not put it over the whole number.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Count how many parts there are altogether. A whole number is worth the denominator in parts.
- Change the 4 wholes into eighths. One whole is
, so 4 wholes are 4 lots of 8.8 8 4 × 8 = 32, so 4 =32 8 - Add the 3 extra eighths. The fraction part is already in the same size parts.32 + 3 = 35
- Write the improper fraction. The denominator stays the same.4
=3 8 35 8
Check. Change back: 35 ÷ 8 = 4 remainder 3, so
Watch out. Multiply the whole number by the denominator, then add the numerator. Do not just write the digits next to each other.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Then add the numerators and keep the denominator.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 10, so 10 will do.10 ÷ 5 = 2, so 5 goes into 10
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.
=4 5 =4 × 2 5 × 2 8 10 - Add the numerators. We are adding parts of the same size, so we add the top numbers. The bottom number stays the same.
+7 10 =8 10 =7 + 8 10 15 10 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 15 ÷ 10.15 10 = 115 10 5 10 - Simplify the fraction part. 5 and 10 can both be divided by 5.
=5 10 =5 ÷ 5 10 ÷ 5 1 2
So the answer is 1 .1 2 - Write the answer.
+7 10 = 14 5 1 2
Check. Take away: 1
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 4, so we can subtract straight away.
- The first fraction part (1) is smaller than the second (3), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 4 quarters, so the numbers become fractions over 4.3
=1 4 =3 × 4 + 1 4 13 4
1 =3 4 =1 × 4 + 3 4 7 4 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−13 4 =7 4 =13 − 7 4 6 4 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 6 ÷ 4.6 4 = 16 4 2 4 - Simplify the fraction part. 2 and 4 can both be divided by 2.
=2 4 =2 ÷ 2 4 ÷ 2 1 2
So the answer is 1 .1 2 - Write the answer. 3
− 11 4 = 13 4 1 2
Check. Add back: 1
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 5 ×
as 5 lots of2 3 . Multiplying by a whole number is repeated addition.2 3 +2 3 +2 3 +2 3 +2 3 2 3 - Multiply the numerator by 5. Keep the denominator. We are counting thirds. 5 lots of 2 thirds is 10 thirds.5 ×
=2 3 =5 × 2 3 10 3 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 10 ÷ 3.10 3 = 310 3 1 3 - Write the answer. 5 ×
= 32 3 1 3
Check. Divide back: 3
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. To find a fraction of an amount, divide by the denominator to find one part. Then multiply by the numerator.
- Divide the amount by the denominator. The denominator 3 tells us to cut the amount into 3 equal parts. One part is
of the amount.1 3 90 minutes ÷ 3 = 30 minutes - Multiply by the numerator. The numerator 2 tells us how many of those parts we want.2 × 30 minutes = 60 minutes
- Write the answer.
of 90 minutes = 60 minutes2 3
Check. Other way: 2 × 90 minutes = 180 minutes, then ÷ 3 = 60 minutes. ✓
Watch out. Divide by the bottom number first. Then multiply by the top number.
Total 19 marks. Allow about 19 minutes.
Exercise 6X SATs-style questions
Non-calculatorKey words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Check each option. An equivalent fraction simplifies to the same fraction as
- Write
in its simplest form. It is already as small as it can be.3 5 3 5 - Simplify each option. Equivalent fractions have the same simplest form.A:
=6 10 → equal3 5
B: (already simplest) → not equal5 8
C: (already simplest) → not equal3 10
D: (already simplest) → not equal6 5 - Pick the equal one. Only one option is equivalent.A (
)6 10
Check.
Watch out. Check the top and the bottom change by the same number.
Key words. Equivalent fractions are different fractions that are worth the same amount, like
Method. Equivalent fractions are made by multiplying the top and the bottom by the same number.
- Look at the bottom numbers. What do we multiply 6 by to get 18? This tells us how the fraction has been changed. We must do the same to the other number.6 × 3 = 18, so the multiplier is 3.
- Do the same to the top number. To keep the fraction the same size, the top and the bottom must both be multiplied by 3.5 × 3 = 15
- Write the equivalent fractions. Now both numbers are filled in.
=5 6 15 18
Check.
Watch out. Whatever you do to the top, do to the bottom. Never add or subtract the same number.
Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. An improper fraction has more parts than one whole. Divide the top by the bottom to find how many whole ones it holds.
- Divide 17 by 5. The fraction line means divide. The answer tells us how many whole ones we can make.17 ÷ 5 = 3 remainder 2
- The whole number is 3. 3 lots of 5 fifths make 3 whole ones: 3 × 5 = 15.17 − 15 = 2 fifths are left over.
- Write the leftover parts as a fraction. The remainder is the numerator. The denominator stays 5.3 and
= 32 5 2 5
Check. Change back: 3 × 5 + 2 = 17 = 17. ✓
Watch out. The leftover (remainder) goes on top of the same denominator. Do not put it over the whole number.
Key words. To order fractions is to put them in a line from the smallest to the largest (ascending) or from the largest to the smallest (descending). Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. Change every fraction to the same denominator. Then order the numerators.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 16, so 16 will do.16 ÷ 2 = 8, so 2 goes into 16
16 ÷ 4 = 4, so 4 goes into 16
16 ÷ 8 = 2, so 8 goes into 16 - Change every fraction to the common denominator. Multiply the top and the bottom by the same number each time.
=5 8 =5 × 2 8 × 2 10 16 =3 4 =3 × 4 4 × 4 12 16 =1 2 =1 × 8 2 × 8 8 16 (already in sixteenths)9 16 - Put the top numbers in order. With the same bottom number, the bigger the top number, the bigger the fraction. We want smallest to largest.8, 9, 10, 12 (out of 16)
- Write the original fractions in that order. The answer uses the fractions from the question, not the changed ones.
,1 2 ,9 16 ,5 8 3 4
Check. Read the numerators again: 8, 9, 10, 12 go up each time. ✓
Watch out. Write down the original fractions in your final answer.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into.
Method. Make sure the denominators are the same. Add the whole numbers, then add the numerators. Change the answer to a mixed number and simplify if you can.
- Find a common denominator. The denominators must be the same before we compare or add. Every smaller denominator goes into 6, so 6 will do.6 ÷ 3 = 2, so 3 goes into 6
- Change the fractions to the common denominator. Multiply the top and the bottom by the same number, so each fraction keeps its value.1
→1 3 =1 3 =1 × 2 3 × 2 2 6 - Add the whole numbers. Add the wholes first, then deal with the fractions.3 + 1 = 4
- Add the fractions. Add the numerators. The denominator stays the same because the parts are the same size.
+5 6 =2 6 =5 + 2 6 7 6 - The fraction part is 1 or more, so change it to a whole number and a fraction.
means 7 ÷ 6.7 6 = 17 6 1 6
4 + 1 = 51 6 1 6 - Write the answer. 3
+ 15 6 = 51 3 1 6
Check. Take away: 5
Watch out. Add the numerators only. The denominator does not get added: 1/4 + 1/4 is 2/4, not 2/8.
Key words. To add or subtract fractions, the denominators (bottom numbers) must be the same. A common denominator is a bottom number that both denominators go into. Key words. An improper fraction has a top number that is bigger than (or equal to) the bottom number, like
Method. Make the denominators the same, then subtract. If the fraction you are taking away is bigger, change both numbers to improper fractions first.
- Check the denominators. To subtract fractions, the parts must be the same size.Both denominators are 6, so we can subtract straight away.
- The first fraction part (1) is smaller than the second (5), so we cannot take them away. Change both numbers to improper fractions. Each whole is worth 6 sixths, so the numbers become fractions over 6.4
=1 6 =4 × 6 + 1 6 25 6
2 =5 6 =2 × 6 + 5 6 17 6 - Subtract the numerators. Now both numbers are fractions with the same denominator.
−25 6 =17 6 =25 − 17 6 8 6 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 8 ÷ 6.8 6 = 18 6 2 6 - Simplify the fraction part. 2 and 6 can both be divided by 2.
=2 6 =2 ÷ 2 6 ÷ 2 1 3
So the answer is 1 .1 3 - Write the answer. 4
− 21 6 = 15 6 1 3
Check. Add back: 1
Watch out. Never take the smaller number from the bigger one in each column (3⅕ − 1⅗ is not 2⅖). Change to improper fractions when you need to.
Key words. To compare fractions is to say which is bigger. < means “is less than” and > means “is greater than”. A common denominator is a bottom number that both denominators go into.
Method. To compare fractions that have different denominators, change them to the same denominator. Then compare the numerators.
- Find a common denominator. We need a number that all the denominators go into. List the multiples of each one until you see a number in every list.Multiples of 5: 5, 10, 15, 20, 25, 30, …, 55, 60
Multiples of 12: 12, 24, 36, 48, 60
The first number in every list is 60. - Change both fractions to the common denominator. Multiply the top and the bottom by the same number each time.
=7 12 =7 × 5 12 × 5 35 60 =3 5 =3 × 12 5 × 12 36 60 - Compare the top numbers. With the same denominator, the bigger numerator is the bigger fraction.35 < 36, so
<35 60 36 60 - Write a sentence to prove it. In a “prove it” question the last line must say what you have shown.No.
=7 12 and35 60 =3 5 , and 35 is less than 36. So36 60 is less than7 12 .3 5
Check. The bars: the
Watch out. Do not guess from the numbers. Show the common denominator and the two new fractions.
Key words. Multiplying a fraction by a whole number is the same as adding the fraction that many times. An improper fraction has a top number bigger than its bottom number.
Method. Multiply the numerator by the whole number and keep the denominator. If the answer is an improper fraction, change it to a mixed number or a whole number.
- Think of 4 ×
as 4 lots of3 8 . Multiplying by a whole number is repeated addition.3 8 +3 8 +3 8 +3 8 3 8 - Multiply the numerator by 4. Keep the denominator. We are counting eighths. 4 lots of 3 eighths is 12 eighths.4 ×
=3 8 =4 × 3 8 12 8 - The answer is 1 or more, so change it to a mixed number or a whole number.
means 12 ÷ 8.12 8 = 112 8 4 8 - Simplify the fraction part. 4 and 8 can both be divided by 4.
=4 8 =4 ÷ 4 8 ÷ 4 1 2
So the answer is 1 .1 2 - Write the answer. 4 ×
= 13 8 1 2
Check. Divide back: 1
Watch out. Multiply the top only. The bottom stays the same: 3 × 2/5 is 6/5, not 6/15.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. Find how many stickers each child gets. Add them and take the total away from 72.
- Find the stickers Leo gets.
of 72.1 4 72 ÷ 4 = 18 - Find the stickers Mei gets.
of 72.1 3 72 ÷ 3 = 24 - Add the stickers given away. Both amounts leave the pile.18 + 24 = 42
- Take them from 72. The rest are left.72 − 42 = 30
Check.
Watch out. Marks: 1 for each fraction of 72, 1 for the answer.
Key words. “Of” means multiply. To find a fraction of an amount, divide by the denominator, then multiply by the numerator.
Method. Find the fraction she has read, then the fraction left. The pages left tell us the value of that fraction.
- Add the fractions she has read. Change to eighths first.
+1 4 =3 8 +2 8 =3 8 5 8 - Find the fraction left. Take it away from 1 whole book.1 −
=5 8 −8 8 =5 8 3 8 - Find one eighth of the book.
of the book is 21 pages, so divide by 3.3 8 21 ÷ 3 = 7 pages - Find the whole book. There are 8 eighths.8 × 7 = 56 pages
Check.
Watch out. Marks: 1 for the fraction left, 1 for one eighth, 1 for the answer.