Follow the following Steps:
- Choose a number with a 3 and repeating 9’s.
- The square is made up of:
Example-1:
- If the number to be squared is 3999:
- The square has:
first digits: 15 and one fewer
9 than 9's 1 5 9 9
next digits: 2 and one fewer
0 than 9's 2 0 0
last digit: 1 1 - So 3999 × 3999 = 15,992,001.
Example-2:
- If the number to be squared is 399999:
- The square has:
first digits: 15 and one fewer
9 than 9's 1 5 9 9 9 9
next digits: 2 and one fewer
0 than 9's 2 0 0 0 0
last digit: 1 1 - So 399999 × 399999 = 159,999,200,001.