Practice Finding Squares Using (a + d)(a - d) + d²
Worksheet Description
Practice squaring numbers up to 200 using (a + d)(a − d) + d². Solve 150 problems mentally from left to right. Linked blog explains the trick visually.
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The Worksheet
The detailed description of the worksheet
This interactive worksheet helps you master the quick mental math trick for finding squares of numbers up to 200 using the identity:
a² = (a + d)(a − d) + d²If you're new to this trick, check out our detailed interactive blog post on squaring numbers up to 200 . There, you can see a visual flow chart showing every step of how the formula works — before returning here to practise it hands-on!
You'll get 150 practice problems where you can type your answers directly — applying the trick mentally and entering the results from left to right, just as mathemagicians prefer to think.
Many mathemagicians and mental-math experts prefer solving problems from left to right, beginning with the higher place values first. It feels more natural and intuitive for quick, in-mind calculations — especially for tricks like this where you adjust around a round number and refine your result step by step.