Step-by-step Maths Level 5: Rounding decimals
Part of the Step-by-step Maths Level 5 decimals to tenths and hundredths chapter. Chapter overview · whole chapter on one page
Rounding decimals
Look at the digit after the place you are rounding to. 5 or more: round up. 4 or less: round down.
To round to the nearest tenth, look at the hundredths. To round to the nearest whole number, look at the tenths.
Key ideas
- Round to the nearest whole number: look at the tenths digit.
- Round to the nearest tenth: look at the hundredths digit.
- Round to the nearest hundredth: look at the thousandths digit.
Method. Look at the digit after the place you are rounding to, then decide.
- Look at the tenths digit. This digit decides whether to round up or down.The digit is 4
- Decide. 5 or more: round up. 4 or less: round down.4 is 4 or less, so round down
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.3
Check. Check: 3 is the closest number with the right number of places to 3.460.
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.
- Look at the hundredths digit. This digit decides whether to round up or down.The digit is 6
- Decide. 5 or more: round up. 4 or less: round down.6 is 5 or more, so round up
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.4.6
Check. Check: 4.6 is the closest number with the right number of places to 4.560.
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.
- Look at the thousandths digit. This digit decides whether to round up or down.The digit is 6
- Decide. 5 or more: round up. 4 or less: round down.6 is 5 or more, so round up
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.4.88
Check. Check: 4.88 is the closest number with the right number of places to 4.876.
Watch out. Round up only on a 5 or more. Do not drop the zero from the tenths when rounding to tenths.
Watch out
Watch out. 3.46 to the nearest tenth is 3.5, not 3.4. Look at the hundredths digit, which is 6.
Exam tip
Grown-up tip. Ask: “Which digit decides? Is it 5 or more?” before the child writes the rounded number.
Exercise 7D Practice: rounding decimals
Non-calculatorMethod. Look at the digit after the place you are rounding to, then decide.
- Look at the hundredths digit. This digit decides whether to round up or down.The digit is 5
- Decide. 5 or more: round up. 4 or less: round down.5 is 5 or more, so round up
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.1.4
Check. Check: 1.4 is the closest number with the right number of places to 1.356.
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.
- Look at the tenths digit. This digit decides whether to round up or down.The digit is 3
- Decide. 5 or more: round up. 4 or less: round down.3 is 4 or less, so round down
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.6
Check. Check: 6 is the closest number with the right number of places to 6.304.
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.
- Look at the hundredths digit. This digit decides whether to round up or down.The digit is 8
- Decide. 5 or more: round up. 4 or less: round down.8 is 5 or more, so round up
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.6.6
Check. Check: 6.6 is the closest number with the right number of places to 6.581.
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.
- Look at the hundredths digit. This digit decides whether to round up or down.The digit is 9
- Decide. 5 or more: round up. 4 or less: round down.9 is 5 or more, so round up
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.7.1
Check. Check: 7.1 is the closest number with the right number of places to 7.097.
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.
- Look at the tenths digit. This digit decides whether to round up or down.The digit is 8
- Decide. 5 or more: round up. 4 or less: round down.8 is 5 or more, so round up
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.3
Check. Check: 3 is the closest number with the right number of places to 2.876.
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.
- Look at the tenths digit. This digit decides whether to round up or down.The digit is 3
- Decide. 5 or more: round up. 4 or less: round down.3 is 4 or less, so round down
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.6
Check. Check: 6 is the closest number with the right number of places to 6.323.
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.
- Look at the thousandths digit. This digit decides whether to round up or down.The digit is 2
- Decide. 5 or more: round up. 4 or less: round down.2 is 4 or less, so round down
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.9.34
Check. Check: 9.34 is the closest number with the right number of places to 9.342.
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.
- Look at the thousandths digit. This digit decides whether to round up or down.The digit is 9
- Decide. 5 or more: round up. 4 or less: round down.9 is 5 or more, so round up
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.3.40
Check. Check: 3.40 is the closest number with the right number of places to 3.399.
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.
- Look at the thousandths digit. This digit decides whether to round up or down.The digit is 4
- Decide. 5 or more: round up. 4 or less: round down.4 is 4 or less, so round down
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.2.00
Check. Check: 2.00 is the closest number with the right number of places to 2.004.
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.
- Look at the thousandths digit. This digit decides whether to round up or down.The digit is 9
- Decide. 5 or more: round up. 4 or less: round down.9 is 5 or more, so round up
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.1.63
Check. Check: 1.63 is the closest number with the right number of places to 1.629.
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.
- Look at the hundredths digit. This digit decides whether to round up or down.The digit is 3
- Decide. 5 or more: round up. 4 or less: round down.3 is 4 or less, so round down
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.9.1
Check. Check: 9.1 is the closest number with the right number of places to 9.131.
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.
- Look at the hundredths digit. This digit decides whether to round up or down.The digit is 0
- Decide. 5 or more: round up. 4 or less: round down.0 is 4 or less, so round down
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.7.9
Check. Check: 7.9 is the closest number with the right number of places to 7.908.
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.
- Look at the thousandths digit. This digit decides whether to round up or down.The digit is 7
- Decide. 5 or more: round up. 4 or less: round down.7 is 5 or more, so round up
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.8.79
Check. Check: 8.79 is the closest number with the right number of places to 8.787.
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.
- Look at the hundredths digit. This digit decides whether to round up or down.The digit is 1
- Decide. 5 or more: round up. 4 or less: round down.1 is 4 or less, so round down
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.2.3
Check. Check: 2.3 is the closest number with the right number of places to 2.312.
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.
- Look at the tenths digit. This digit decides whether to round up or down.The digit is 6
- Decide. 5 or more: round up. 4 or less: round down.6 is 5 or more, so round up
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.5
Check. Check: 5 is the closest number with the right number of places to 4.649.
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.
- Look at the thousandths digit. This digit decides whether to round up or down.The digit is 8
- Decide. 5 or more: round up. 4 or less: round down.8 is 5 or more, so round up
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.3.53
Check. Check: 3.53 is the closest number with the right number of places to 3.528.
Watch out. Round up only on a 5 or more. Do not drop the zero from the tenths when rounding to tenths.