Maths Library

Rounding and Estimating: Year 4 maths

This topic covers rounding whole numbers to powers of ten (10, 100, 1,000, etc.) and using rounded values to estimate calculations. Pupils practise identifying adjacent multiples and applying convention rules for the halfway boundary.

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What this covers

Rounding and Estimating is taught in Year 4 (age 9 to 10) as a topic to introduce. It sits in the Number strand.

Worked example

Round 468 to the nearest 10.

  1. Identify the two surrounding multiples of 10: 460 and 470.
  2. Look at the ones digit: it is 8.
  3. Since 8 is 5 or greater, round up to 470.

Answer: 470

Difficulty scale

The sheet generator offers five difficulty settings for this topic.

  1. Rounding 2-digit numbers to the nearest 10 using a marked number line
  2. Rounding 3-digit numbers to the nearest 10 or 100
  3. Rounding 4-digit numbers to the nearest 10, 100, or 1,000
  4. Rounding large whole numbers to any given power of ten up to 100,000
  5. Estimating the answers to multi-step calculations by prior rounding

Common mistakes

  • Always rounding down when the target digit is followed by 5 instead of rounding up
  • Changing subsequent digits to non-zero values after rounding

Curriculum links

Indicative matches to Australian Curriculum v9. Check wording and codes against the official document.

  • AC9M4N01 Order and represent numbers of any size up to at least tens of thousands using place value.

Sample sheet and answers

Six questions at the level's usual difficulty. Open the editor to change, add or regenerate any of them.

Rounding and Estimating

Year 4 maths

Qs
6
Marks
6
NameDateScore / 6
1.
Round 5545 to the nearest hundred.
[1]
2.
Round 8219 to the nearest hundred.
[1]
3.
Round 7442 to the nearest hundred.
[1]
4.
Round 8913 to the nearest hundred.
[1]
5.
Round 9045 to the nearest hundred.
[1]
6.
Round 7694 to the nearest hundred.
[1]

Answer key

  1. 5500Look at the digit to the right of the hundreds place; 5545 rounds to 5500
  2. 8200Look at the digit to the right of the hundreds place; 8219 rounds to 8200
  3. 7400Look at the digit to the right of the hundreds place; 7442 rounds to 7400
  4. 8900Look at the digit to the right of the hundreds place; 8913 rounds to 8900
  5. 9000Look at the digit to the right of the hundreds place; 9045 rounds to 9000
  6. 7700Look at the digit to the right of the hundreds place; 7694 rounds to 7700