Finding the square root of 2-digit numbers ending in 1

Follow the following Steps:

1. Select a 2-digit number and square it.
2. Drop the last two digits of the square.
3. Find the largest square root of the remaining digits.
   This is first digit of the square root.
4. The second digit is 1.

   Examples:1

1. If the square is 2601:
2. Drop the last two digits: 26
3. Find the largest root in 26: 5 × 5 = 25
4. The first digit is 5. The second digit is 1.
5. So the square root of 2601 is 51.   

Examples:2

1. If the square is 8281:
2. Drop the last two digits: 82
3. Find the largest root in 82: 9 × 9 = 81
4. The first digit is 9. The second digit is 1.
5. So the square root of 2601 is 91.