Rounding Decimals: Nearest Whole & 1 d.p.

D6Rounding Decimals

Find the nearest whole number or tenth.

Rounding gives a simpler number that's close to the original.

Round 3.47 to 1 decimal place.

3.47 → 3.5

3.47 is closer to 3.5 than to 3.4 — the 7 hundredths round the tenths up.

Learn the 3-Step Method

1Find the rounding digit.

Rounding to 1 d.p.? The rounding digit is the tenths digit.

3.47

2Look at the next digit.

The digit to its right decides: 5 or more → round up; 4 or less → keep.

3.47 → up

3Round and drop the rest.

3.47 → 3.5. Everything after the rounding place disappears.

3.5

💡 Key IdeaThe digit one place to the right makes the decision. 5, 6, 7, 8, 9 → round up. 0, 1, 2, 3, 4 → stay.

Worked Example

Round each number.

To the nearest whole

3.47 → look at tenths (4)

3.47 → 3

To 1 decimal place

2.86 → look at hundredths (6)

2.86 → 2.9

The tricky one

2.97 → 9 rounds up to 10

2.97 → 3.0

Watch Out! Common Mistakes

Looking at the wrong digit.

3.44 → 3.5 ✕

Wrong! The hundredths digit is 4, so the tenths stay: 3.44 → 3.4.

Rounding twice.

3.449 → 3.45 → 3.5 ✕

Wrong! Round in one step from the original: 3.449 → 3.4 (the hundredths digit is 4).

Dropping the .0.

2.97 → 3 ✕ (to 1 d.p.)

Careful! To 1 decimal place the answer is 3.0 — the .0 shows the accuracy asked for.

⬇ Cheat Sheet

ROUNDING DECIMALS

Underline the rounding digit.
Look ONE place to the right.
5 or more → round up; 4 or less → keep.
Drop everything after the rounding place (keep a .0 if asked for 1 d.p.).

Examples: 3.47 → 3.5 (1 d.p.) · 3.47 → 3 (whole) · 2.97 → 3.0 (1 d.p.)

📖 Continue Your Journey

✓ D1 What Are Decimals?✓ D2 Place Value in Decimals ✓ D3 Decimals on a Number Line ✓ D4 Comparing Decimals ✓ D5 Ordering Decimals D6 Rounding Decimals D7 Adding Decimals D8 Subtracting Decimals D9 Multiplying by 10, 100 and 1000 D10 Dividing by 10, 100 and 1000 D11 Multiplying Decimals by Whole Numbers D12 Dividing Decimals by Whole Numbers D13 Fractions to Decimals D14 Decimal Problem Solving

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Next Lesson: D7 Adding DecimalsLine up the points. Add column by column.

📄 Free printable: Download the Rounding Decimals cheat sheet (PDF) — keep it by your child's desk.

Quick summary

Underline the digit you're rounding to; the digit to its right decides.
5 or more rounds up; 4 or less keeps the digit the same.
Round in one step from the original number, never in stages.
When rounding to 1 d.p., keep the .0 — 2.97 rounds to 3.0.

Frequently asked questions

What is the rule for rounding decimals?

Find the digit in the place you're rounding to, then look at the digit immediately to its right: 5 or more, round up; 4 or less, leave it. Then drop the remaining digits.

What does '1 decimal place' mean?

One digit after the decimal point. Rounding 3.47 to 1 d.p. gives 3.5; rounding it to the nearest whole number gives 3.

Why does 2.97 round to 3.0 and not 3?

Both describe the same value, but writing 3.0 shows you rounded to one decimal place, which is what the question asked for. In exams the .0 can matter.