0Here is the easiest way to find squares of adjacent numbers
12 * 12 = 144
13 * 13 = 144 + 12 + 13
14 * 14 = 144 + 12 + 13 + 13 + 14.
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59 * 59 = (60 * 60) - 60 - 59 = 3600 - 60 - 59=3481
58 * 58 = 3600 - 60 - 59 - 59 - 58 = 3364
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Squares of any number ending with 5 can be find out using Antyayor Dasakepi.
eg: 15 * 15 = 1 * 2|25 = 225 (multiply the number in the tenth place with the next number).
25 * 25 = 2 * 3|25 = 625
35 * 35 = 3 * 4|25 = 1225
75 * 75 = 7 * 8|25 = 5625
So, by regular practicing the above two methods, squares of any 2-digit number can be calculated mentally and in seconds.
