Step-by-step Maths Level 5 Decimals to tenths and hundredths: check-up and practice test questions

Method. Line up the decimal points and add in columns. Keep the pound sign and two places for pence.

1. Line up the decimal points. Write the pounds and pence in columns.
   1.40 + 1.91
2. Add the pence first. Carry any ten pence into the pounds.
   40 + 91 = 131 pence
3. Add the pounds. Include any carried pounds.
   1 + 1 = 3 pounds
4. Write the answer with the pound sign. Always write two places for the pence.
   £3.31

Check. Check: £3.31 - £1.91 = £1.40.

Watch out. Always write two digits for the pence: £5.00, not £5.

Method. Look at the digit after the place you are rounding to, then decide.

1. Look at the hundredths digit. This digit decides whether to round up or down.
   The digit is 3
2. Decide. 5 or more: round up. 4 or less: round down.
   3 is 4 or less, so round down
3. Write the rounded number. Make the digits after the rounding place zero, or leave them out.
   3.3

Check. Check: 3.3 is the closest number with the right number of places to 3.333.

Watch out. Round up only on a 5 or more. Do not drop the zero from the tenths when rounding to tenths.

Method. Write the whole number, then one digit for the tenths and two digits for the hundredths.

1. Write the whole number first. This is the part before the decimal point.
   9
2. Write the tenths and the hundredths after the point. 8/10 is one place, and 3/100 is two places.
   9.83
3. Write the answer. Check that each digit is in the right place.
   9.83

Check. Check: 9.83 = 9 + 0.8 + 0.03, when h is a single digit.

Watch out. Use two places for hundredths. The hundredths digit is the second place after the point.

Method. Look at the digit after the place you are rounding to, then decide.

1. Look at the tenths digit. This digit decides whether to round up or down.
   The digit is 1
2. Decide. 5 or more: round up. 4 or less: round down.
   1 is 4 or less, so round down
3. Write the rounded number. Make the digits after the rounding place zero, or leave them out.
   4

Check. Check: 4 is the closest number with the right number of places to 4.170.

Watch out. Round up only on a 5 or more. Do not drop the zero from the tenths when rounding to tenths.

Method. Find the tenths, then count the hundredths beyond them.

1. Find the tenths either side. Read the tenths labels to find the gap.
   The mark is between 0.80 and 0.90
2. Count the small steps. Each small step is one hundredth.
   2 hundredths past 0.80
3. Write the decimal. Two places after the point.
   0.82

Check. Check: 0.82 is 82 hundredths, which is 82/100.

Watch out. There are ten small steps between two tenths marks, so each small step is a hundredth.

Method. Write the whole number, then one digit for the tenths and two digits for the hundredths.

1. Write the whole number first. This is the part before the decimal point.
   2
2. Write the tenths and the hundredths after the point. 3/10 is one place, and 9/100 is two places.
   2.39
3. Write the answer. Check that each digit is in the right place.
   2.39

Check. Check: 2.39 = 2 + 0.3 + 0.09, when h is a single digit.

Watch out. Use two places for hundredths. The hundredths digit is the second place after the point.

Method. Find the tenths, then count the hundredths beyond them.

1. Find the tenths either side. Read the tenths labels to find the gap.
   The mark is between 0.80 and 0.90
2. Count the small steps. Each small step is one hundredth.
   8 hundredths past 0.80
3. Write the decimal. Two places after the point.
   0.88

Check. Check: 0.88 is 88 hundredths, which is 88/100.

Watch out. There are ten small steps between two tenths marks, so each small step is a hundredth.

Method. Line up the decimal points, then add in columns, keeping the unit.

1. Line up the decimal points. Add the metres and the centimetres in the right places.
   2.29 + 2.16
2. Add the hundredths and tenths. Carry where needed.
   45 hundredths in total
3. Write the total length with the unit. Give the answer in metres, to two places.
   4.45 m

Check. Check: 4.45 - 2.16 = 2.29.

Watch out. Write the unit in the answer: 1.85 m, not 1.85.

Method. A zero at the end of a decimal does not change its value.

1. Add a zero at the end. Adding a zero after the last digit does not change the value.
   9.8 = 9.80
2. Compare the two numbers. The tenths digit and the zero in the hundredths are both empty places.
   9.80 = 9.8
3. Write the answer. They are equal; the zero only shows that there are no hundredths.
   9.80

Check. Check: 98/10 = 980/100.

Watch out. 0.5 and 0.50 are equal. The zero at the end does not make the number bigger.

Method. The second digit after the point is the number of hundredths.

1. Find the hundredths digit. It is the second digit after the decimal point.
   The digit is 7
2. Write its value. 7 hundredths is 7/100.
   7/100 = 0.07
3. Write the answer. The value is a decimal with the digit in the second place.
   0.07

Check. Check: in 8.47 the second digit after the point is 7, so the value is 7/100 = 0.07.

Watch out. The value is 0.0 with the digit after it: 0.07, not 0.7.

Method. Compare the whole numbers, then the tenths, then the hundredths.

1. Compare the whole numbers. Put the smallest whole number first.
   3, 3, 7, 8
2. Compare the tenths and hundredths. Use the next places to put the rest in order.
   3.36, 3.62, 7.07, 8.81
3. Write the list smallest first. Check each pair in order.
   3.36, 3.62, 7.07, 8.81

Check. Check: each number is smaller than the one after it.

Watch out. Do not order by the number of digits. Compare the places from the left.

Method. Look at the digit after the place you are rounding to, then decide.

1. Look at the thousandths digit. This digit decides whether to round up or down.
   The digit is 8
2. Decide. 5 or more: round up. 4 or less: round down.
   8 is 5 or more, so round up
3. Write the rounded number. Make the digits after the rounding place zero, or leave them out.
   6.99

Check. Check: 6.99 is the closest number with the right number of places to 6.988.

Watch out. Round up only on a 5 or more. Do not drop the zero from the tenths when rounding to tenths.

Method. Compare the digits from the left: whole numbers, then tenths, then hundredths.

1. Compare the whole numbers. The bigger whole number is the bigger decimal.
   2 and 8
2. Compare the tenths. If the whole numbers match, the tenths decide.
   5 and 7 tenths
3. Compare the hundredths. If the tenths also match, the hundredths decide.
   2 and 9 hundredths
4. Choose the greater number. This is the number with the larger digit in the first place they differ.
   8.79

Check. Check: 8.79 is 879 hundredths and 2.52 is 252 hundredths.

Watch out. Do not think 0.45 is bigger than 0.5 because 45 is bigger than 5. Compare the tenths first.

Method. Look at the digit after the place you are rounding to, then decide.

1. Look at the thousandths digit. This digit decides whether to round up or down.
   The digit is 9
2. Decide. 5 or more: round up. 4 or less: round down.
   9 is 5 or more, so round up
3. Write the rounded number. Make the digits after the rounding place zero, or leave them out.
   2.13

Check. Check: 2.13 is the closest number with the right number of places to 2.129.

Watch out. Round up only on a 5 or more. Do not drop the zero from the tenths when rounding to tenths.

Method. Look at the digit after the place you are rounding to, then decide.

1. Look at the tenths digit. This digit decides whether to round up or down.
   The digit is 4
2. Decide. 5 or more: round up. 4 or less: round down.
   4 is 4 or less, so round down
3. Write the rounded number. Make the digits after the rounding place zero, or leave them out.
   2

Check. Check: 2 is the closest number with the right number of places to 2.472.

Watch out. Round up only on a 5 or more. Do not drop the zero from the tenths when rounding to tenths.

Method. The second digit after the point is the number of hundredths.

1. Find the hundredths digit. It is the second digit after the decimal point.
   The digit is 5
2. Write its value. 5 hundredths is 5/100.
   5/100 = 0.05
3. Write the answer. The value is a decimal with the digit in the second place.
   0.05

Check. Check: in 4.55 the second digit after the point is 5, so the value is 5/100 = 0.05.

Watch out. The value is 0.0 with the digit after it: 0.07, not 0.7.

Method. The second digit after the point is the number of hundredths.

1. Find the hundredths digit. It is the second digit after the decimal point.
   The digit is 7
2. Write its value. 7 hundredths is 7/100.
   7/100 = 0.07
3. Write the answer. The value is a decimal with the digit in the second place.
   0.07

Check. Check: in 1.07 the second digit after the point is 7, so the value is 7/100 = 0.07.

Watch out. The value is 0.0 with the digit after it: 0.07, not 0.7.

Method. The second digit after the point is the number of hundredths.

1. Find the hundredths digit. It is the second digit after the decimal point.
   The digit is 5
2. Write its value. 5 hundredths is 5/100.
   5/100 = 0.05
3. Write the answer. The value is a decimal with the digit in the second place.
   0.05

Check. Check: in 2.75 the second digit after the point is 5, so the value is 5/100 = 0.05.

Watch out. The value is 0.0 with the digit after it: 0.07, not 0.7.

Method. Compare the whole numbers, then the tenths, then the hundredths.

1. Compare the whole numbers. Put the smallest whole number first.
   1, 7, 7, 5
2. Compare the tenths and hundredths. Use the next places to put the rest in order.
   1.84, 7.16, 7.13, 5.71
3. Write the list smallest first. Check each pair in order.
   1.84, 5.71, 7.13, 7.16

Check. Check: each number is smaller than the one after it.

Watch out. Do not order by the number of digits. Compare the places from the left.

Method. Compare the whole numbers, then the tenths, then the hundredths.

1. Compare the whole numbers. Put the smallest whole number first.
   7, 2, 4, 2
2. Compare the tenths and hundredths. Use the next places to put the rest in order.
   7.19, 2.71, 4.00, 2.82
3. Write the list smallest first. Check each pair in order.
   2.71, 2.82, 4.00, 7.19

Check. Check: each number is smaller than the one after it.

Watch out. Do not order by the number of digits. Compare the places from the left.