GurooHow to square numbers near 50 in your head
Numbers close to 50 have a neat shortcut, built on the fact that 50² is 2500.
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Download the free worksheet (PDF)
Worksheet includes an answer key for grown-ups
How it works
- Find the gap from 50.
- Add the gap to 25 (take it away if below 50). That gives the hundreds.
- Square the gap for the last two digits.
Worked example
53²: the gap is 3. 25 + 3 = 28. 3² = 09. Answer: 2809.
Top tip
Below 50, subtract: 47², gap 3, 25 − 3 = 22, 3² = 09, so 2209.
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