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