Square 2 Digit Number: UP-DOWN Method

Square a 2 Digit Number, for this example 37:

    * Look for the nearest 10 boundary
    * In this case up 3 from 37 to 40.
    * Since you went UP 3 to 40 go DOWN 3 from 37 to 34.
    * Now mentally multiply 34x40
    * The way I do it is 34x10=340;
    * Double it mentally to 680
    * Double it again mentally to 1360
    * This 1360 is the FIRST interim answer.
    * 37 is "3" away from the 10 boundary 40.
    * Square this "3" distance from 10 boundary.
    * 3x3=9 which is the SECOND interim answer.
    * Add the two interim answers to get the final answer.
    * Answer: 1360 + 9 = 1369