Apply the examples with Rounding Calculator. Check the worked steps below, then practice on your own.
The standard rounding rule
First identify the requested precision: whole number, one decimal place, two decimal places, and so on. Then inspect the first digit that would be removed. Under the common round-half-up school rule, digits 0 through 4 leave the kept digit unchanged and digits 5 through 9 increase it.
Some scientific and software systems use a different tie-breaking rule, such as round-half-to-even. When an exact 5 sits at a tie, confirm which rule your task requires.
Worked rounding examples
| Original | Round to | Result | Reason |
|---|---|---|---|
| 12.347 | 2 decimal places | 12.35 | Third digit is 7 |
| 5.624 | 1 decimal place | 5.6 | Second digit is 2 |
| 9.996 | 2 decimal places | 10.00 | Carry moves into whole part |
| 43.49 | Whole number | 43 | Tenths digit is 4 |
How to round to tenths
The tenths place is the first digit after the point. In 7.86, the tenths digit is 8 and the hundredths digit is 6. The 6 causes the 8 to increase to 9, so the answer is 7.9.
For 7.83, the hundredths digit is 3; the result to one decimal place is 7.8.
How to round to hundredths
The hundredths place is the second digit after the point. In 0.456, look at the thousandths digit, 6. Rounding to two decimal places gives 0.46.
For money, two decimal places often represent cents, but intermediate calculations may need more precision until the final amount is determined.
Negative numbers and midpoint rules
For a negative decimal such as −3.746, rounding to two decimal places produces −3.75 under ordinary nearest-value rounding. Avoid simply chopping off digits, because truncation is not rounding.
Exactly halfway cases are special: 2.345 to two decimals may be 2.35 under half-up, but some computing environments use other rules. The website Rounding Calculator can help you compare a stated precision with the resulting difference.
Try these rounding exercises
- 8.762 to one decimal place: 8.8.
- 0.0986 to two decimal places: 0.10.
- 123.4567 to three decimals: 123.457.
- 14.04 to one decimal place: 14.0.
Keep the requested number of decimal places in a reported answer, even if the final digit is zero.
Frequently asked questions
What is 0.0986 rounded to two decimal places?
0.10, because the third decimal digit is 8 and the hundredths digit increases.
Does rounding change the original calculation?
It changes the reported approximation, not the exact value used in any earlier calculation.
Why is half-up different from half-even?
They use different rules for exact halfway cases; half-even selects the nearest value whose last retained digit is even.
Open the Rounding Calculator, then explore Rounding Windows Game for more practice.