Year 2: Thirds and quarters of a shape
Part of the Year 2 fractions chapter. Chapter overview · whole chapter on one page
Thirds and quarters of a shape
A fraction tells us about equal parts.
A third is one of three equal parts. We write it as 1/3.
A quarter is one of four equal parts. We write it as 1/4.
The bottom number tells how many equal parts there are.
Key ideas
- The bottom number is how many equal parts there are.
- The top number is how many parts are shaded.
- A third is one of three equal parts: 1/3.
- A quarter is one of four equal parts: 1/4.
Key words. The bottom number is how many equal parts there are. The top number is how many parts are shaded.
Method. Count the equal parts underneath. Count the shaded parts on top.
- Count the equal parts. All the parts are the same size. There are 3.3 equal parts
- Count the shaded parts. 1 of the 3 equal parts are shaded.1 shaded
- Write the fraction. The shaded parts go on top. All the equal parts go underneath. That is one third.1/3
Check. Say it in words: one third. ✓
Watch out. The bottom number counts all the equal parts. The top number counts only the shaded parts.
Key words. The bottom number is how many equal parts there are. The top number is how many parts are shaded.
Method. Count the equal parts underneath. Count the shaded parts on top.
- Count the equal parts. All the parts are the same size. There are 4.4 equal parts
- Count the shaded parts. 1 of the 4 equal parts are shaded.1 shaded
- Write the fraction. The shaded parts go on top. All the equal parts go underneath. That is one quarter.1/4
Check. Say it in words: one quarter. ✓
Watch out. The bottom number counts all the equal parts. The top number counts only the shaded parts.
Method. Count the equal parts before you name the fraction.
- Count the equal parts. The shape has 3 equal parts, not 4.3 equal parts
- Count the shaded parts. One of the 3 parts is shaded.1 shaded
- Write the fraction. One of three equal parts is one third, not one quarter.1/3
Check. Three equal parts, one shaded: one third. ✓
Watch out. Count the equal parts first. Four parts would make a quarter.
Watch out
Watch out: the bottom number counts all the equal parts.
It does not count only the shaded parts.
Exam tip
Grown-up tip. Fold a paper circle or square into equal parts. Ask: “How many equal parts? How many are shaded?”
Exercise 4A Thirds and quarters of a shape
Non-calculatorKey words. The bottom number is how many equal parts there are. The top number is how many parts are shaded.
Method. Count the equal parts underneath. Count the shaded parts on top.
- Count the equal parts. All the parts are the same size. There are 3.3 equal parts
- Count the shaded parts. 1 of the 3 equal parts are shaded.1 shaded
- Write the fraction. The shaded parts go on top. All the equal parts go underneath. That is one third.1/3
Check. Say it in words: one third. ✓
Watch out. The bottom number counts all the equal parts. The top number counts only the shaded parts.
Key words. The bottom number is how many equal parts there are. The top number is how many parts are shaded.
Method. Count the equal parts underneath. Count the shaded parts on top.
- Count the equal parts. All the parts are the same size. There are 4.4 equal parts
- Count the shaded parts. 1 of the 4 equal parts are shaded.1 shaded
- Write the fraction. The shaded parts go on top. All the equal parts go underneath. That is one quarter.1/4
Check. Say it in words: one quarter. ✓
Watch out. The bottom number counts all the equal parts. The top number counts only the shaded parts.
Key words. The bottom number is how many equal parts there are. The top number is how many parts are shaded.
Method. Count the equal parts underneath. Count the shaded parts on top.
- Count the equal parts. All the parts are the same size. There are 3.3 equal parts
- Count the shaded parts. 1 of the 3 equal parts are shaded.1 shaded
- Write the fraction. The shaded parts go on top. All the equal parts go underneath. That is one third.1/3
Check. Say it in words: one third. ✓
Watch out. The bottom number counts all the equal parts. The top number counts only the shaded parts.
Key words. The bottom number is how many equal parts there are. The top number is how many parts are shaded.
Method. Count the equal parts underneath. Count the shaded parts on top.
- Count the equal parts. All the parts are the same size. There are 4.4 equal parts
- Count the shaded parts. 1 of the 4 equal parts are shaded.1 shaded
- Write the fraction. The shaded parts go on top. All the equal parts go underneath. That is one quarter.1/4
Check. Say it in words: one quarter. ✓
Watch out. The bottom number counts all the equal parts. The top number counts only the shaded parts.
Method. Equal parts are the same size. Compare the parts to decide.
- Look at each part. Compare the parts side by side.3 parts
- Compare the sizes. Equal parts are the same size.The parts are not the same size.
- Decide. No. The parts are not equal.
Check. Measure the parts with a ruler. The same length means equal. ✓
Watch out. A line that looks like it is in the middle may not be. Check before you decide.
Method. Equal parts are the same size. Compare the parts to decide.
- Look at each part. Compare the parts side by side.3 parts
- Compare the sizes. Equal parts are the same size.The parts are the same size.
- Decide. Yes. The parts are equal.
Check. Measure the parts with a ruler. The same length means equal. ✓
Watch out. A line that looks like it is in the middle may not be. Check before you decide.
Method. Look at each picture and find the one with one third shaded.
- Look at A. Count the equal parts and the shaded parts.A: 4 equal parts, 1 shaded
- Look at B. Count the equal parts and the shaded parts.B: 3 equal parts, 1 shaded
- Look at C. Count the equal parts and the shaded parts.C: 4 equal parts, 2 shaded
- Find the picture that matches. We want the picture with one third shaded.Matches: B
- Write the answer. B
Check. A and C do not match. ✓
Watch out. Count the equal parts first, then the shaded parts.
Key words. The bottom number is how many equal parts there are. The top number is how many parts are shaded.
Method. Count the equal parts underneath. Count the shaded parts on top.
- Count the equal parts. All the parts are the same size. There are 4.4 equal parts
- Count the shaded parts. 1 of the 4 equal parts are shaded.1 shaded
- Write the fraction. The shaded parts go on top. All the equal parts go underneath. That is one quarter.1/4
Check. Say it in words: one quarter. ✓
Watch out. The bottom number counts all the equal parts. The top number counts only the shaded parts.
Key words. The bottom number is how many equal parts there are. The top number is how many parts are shaded.
Method. Count the equal parts underneath. Count the shaded parts on top.
- Count the equal parts. All the parts are the same size. There are 3.3 equal parts
- Count the shaded parts. 1 of the 3 equal parts are shaded.1 shaded
- Write the fraction. The shaded parts go on top. All the equal parts go underneath. That is one third.1/3
Check. Say it in words: one third. ✓
Watch out. The bottom number counts all the equal parts. The top number counts only the shaded parts.
Method. Count the equal parts before you decide.
- Count the equal parts. The circle has 3 equal parts, not 4.3 equal parts
- Count the shaded parts. One of the 3 parts is shaded.1 shaded
- Decide. One of three equal parts is one third, not one quarter.No. It is one third.
Check. Count the parts again: 1, 2, 3. ✓
Watch out. Count the equal parts first.
Method. Look at each picture and find the one with 4 equal parts.
- Look at A. Count the equal parts and the shaded parts.A: 3 equal parts, 0 shaded
- Look at B. Count the equal parts and the shaded parts.B: 4 equal parts, 0 shaded
- Find the picture that matches. We want the picture with 4 equal parts.Matches: B
- Write the answer. B
Check. A do not match. ✓
Watch out. Count the equal parts first, then the shaded parts.
Method. Compare the two shaded parts.
- Look at Ella. Her square has 4 equal parts. One part is a quarter.1/4
- Look at Sam. His circle has 3 equal parts. One part is a third.1/3
- Compare them. Fewer equal parts means each part is bigger. A third is bigger than a quarter.1/3 is bigger than 1/4
- Write the answer. Sam. One third is bigger than one quarter.
Check. Four quarters make one whole, and so do three thirds. Thirds are bigger. ✓
Watch out. More equal parts means each part is smaller.
Method. Compare the sizes of the parts.
- Look at a third. One third is one of three equal parts.Three parts
- Look at a quarter. One quarter is one of four equal parts.Four parts
- Compare. Fewer parts means bigger parts, so a third is bigger.No. A third is bigger than a quarter.
Check. Three equal parts fill a circle, and four equal parts fill it too. ✓
Watch out. More equal parts means each part is smaller.