Simple Method for Calculating Shortcut for Square - Part 2

We've already seen how to find the squares of numbers which are one more than those whose squares we already know (eg 25, 30, 35 etc).Read that post Here. Similarly, we can find the squares of numbers which are one less than the numbers whose squares are known already to us. For Example,

292 = 30 - 30th odd number = 900 - 59 = 841

392 = 40 - 40th odd number = 1600 - 79 = 1521

342 = 1225 - 69 = 1156

542 = 3025 - 109 = 2916

742 = 5625 - 149 = 5476

942 = 9025 - 189 = 8836

2142 = 46225 - 429 = 45796

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