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Square areas with a round sum

Mental mathEasy

A square plot of side m has a square plot of side m cut out of it. How many square m remain?

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A whole number, a decimal, a fraction like 3/8 or a percent.

Hint

The sides add to a round number.

Solution
  1. The area left is .
  2. Factor: .
  3. That is .
  4. The remaining area is .

Answer: