How to square numbers near 100 in your head

For ages 9 to 11 (Years 5 and 6) · 2-minute read · free worksheet

Squaring numbers near 100 becomes simple once you think about how far they are from 100.

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Worksheet includes an answer key for grown-ups

How it works

  1. Find the gap from 100.
  2. Add the gap to the number (take it away if below 100). That is the first part.
  3. Square the gap for the last two digits.

Worked example

103²: the gap is 3. 103 + 3 = 106. 3² = 09. Answer: 10609.

Top tip

Below 100: 97², gap 3, 97 − 3 = 94, 3² = 09, so 9409.
How to square numbers near 100 in your head: 103² = ? 103 + 3 = 106, 3² = 09: 10609

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