Rounding decimals

To round a decimal, look at the digit just to the right of the place you are rounding to: 5 or more, round up; 4 or less, round down. Then drop the digits after it. 3.47 to the nearest tenth is 3.5. This page shows why on a number line, covers rounding to whole numbers, tenths and hundredths, and the tricky case of rounding up past a 9.

Rounding decimals on a number line

Type a decimal and choose “nearest tenth”, “nearest hundredth” or “nearest whole number”.

How to round decimals, step by step

  1. Find the rounding place: tenths is the first digit after the point, hundredths the second.
  2. Look one place to the right.
  3. 5 or more: add 1 to the rounding digit. 4 or less: leave it.
  4. Drop every digit after the rounding place. (Don’t replace them with zeros, unlike whole numbers.)

Worked examples

3.47 to the nearest tenth

Look at 7: round up. 3.5.

6.832 to the nearest hundredth

Look at 2: round down. 6.83.

12.6 to the nearest whole number

Look at 6: round up. 13.

4.96 to the nearest tenth

Look at 6: round up. 9 tenths + 1 = 10 tenths = 1 whole: 5.0.

Rounding money

Prices round to the nearest dollar (nearest whole number) for estimating: $4.79 is about $5, $12.25 is about $12. Calculations with money round to the nearest cent (hundredth).

Common mistakes

3.47 → 3.4Truncated instead of rounding.Fix: look at the next digit: 7 means round up, 3.5.
3.47 → 3.50 or 3.4700Added zeros after rounding.Fix: drop the digits: 3.5.
4.96 → 4.10Wrote 10 in the tenths place.Fix: 10 tenths is 1 whole: 5.0.
Rounded to the wrong placeMixed up tenths and hundredths.Fix: tenths is the first digit after the point.

How to teach it at home

Price estimates

Round shopping prices to the nearest dollar and keep a running total.

Sports times

Round race times to the nearest tenth of a second.

Measurements

Round heights in meters to one decimal place.

By grade

Worksheets and practice

Rounding decimals worksheet, page 1

Rounding decimals worksheet: printable PDF with an answer key. · Make a fresh test

All decimals · Rounding chart

Last reviewed

Questions parents ask

How do you round a decimal to the nearest tenth?

Look at the hundredths digit. If it is 5 or more, round the tenths up; if 4 or less, leave it. Then drop the rest.

How do you round to the nearest hundredth?

Look at the thousandths digit and use the same 5-or-more rule.

What is 4.96 rounded to the nearest tenth?

5.0. The 9 tenths become 10 tenths, which is one more whole.

Do you add zeros when rounding decimals?

No. Drop the digits after the rounding place. 3.47 rounds to 3.5, not 3.50.

What grade learns rounding decimals?

Grade 5 (5.NBT.A.4).