Algebra för Ma1A

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Från Quora:

Wu's Squaring Trick, named after the famous Scott Wu, is a technique used to quickly square numbers over 25 in your head. It uses the identity

n^2 = (n-25) \cdot 100 + (n-50)^2

For example,

62^2 = 37 \cdot 100 + 12^2 = 3844

44^2 = 19 \cdot 100 + 6^2 = 1936

77^2 = 52 \cdot 100 + 27^2 = 5929

These mental computations can be done very quickly with just a little practice, so amaze your friends with how fast you can square two digit numbers!