To square 2-digit numbers ending with 5: ex. 652 = 4225
-Multiply the tens digit of the number being squared times its next higher digit. This yields the hundreds digit(s) of the answer. ex. The next higher digit to 6 is 7, so 6 x 7 = 42 for an answer of 42_ _.
-Because 5 is the ones digit being squared, the last two digits of the answer are always 25. ex. _ _ 25