Rounding to decimal places
When rounding using decimal placesThe number of digits required after the decimal point when rounding a decimal answer.(dp), the degree of accuracy that is required is usually given. However, there are certain calculations where the degree of accuracy may be more obvious. For example, calculations involving money should be given to two decimal places to represent the pence.
To round to a decimal place:
- look at the first digit after the decimal point if rounding to one decimal place or the second digit for two decimal places
- draw a vertical line to the right of the place value digit that is required
- look at the next digit
- if it’s 5 or more, increase the previous digit by 1
- if it’s 4 or less, keep the previous digit the same
- remove any numbers to the right of the line
Examples
Round 248.561 to one and two decimal places.
- 248.5|61 to one decimal place is 248.6
- 248.56|1 to two decimal places is 248.56
Notice that your answer should have the same number of decimal places as the approximation asked for.
Round 0.08513 to one and two decimal places.
- 0.0|8513 to one decimal place is 0.1
- 0.08|513 to two decimal places is 0.09
Question
Round 249.5046 to one and two decimal places.
- 249.5|046 to one decimal place is 249.5
- 249.50|46 to two decimal places is 249.50
Notice that 249.50 = 249.5. However, as the question asked for 2 decimal places both numbers are left.
Question
Round 0.9583 to one and two decimal places.
- 0.9|583 to one decimal place is 1.0
- 0.95|83 to two decimal places is 0.96
Question
Round 598.053 to one and two decimal places.
- 598.0|53 to one decimal place is 598.1
- 598.05|3 to two decimal places is 598.05