Squaring a 2-digit number ending in 2
1. Take a 2-digit number ending in 2.
2. The last digit will be _ _ _ 4.
3. Multiply the first digit by 4: the 2nd number will be
the next to the last digit: _ _ X 4.
4. Square the first digit and add the number carried from
the previous step: X X _ _.
Example:
1. If the number is 52, the last digit is _ _ _ 4.
2. 4 × 5 = 20 (four times the first digit): _ _ 0 4.
3. 5 × 5 = 25 (square the first digit), 25 + 2 = 27 (add carry): 2 7 0 4.
4. So 52 × 52 = 2704.
