@msrebeccablack now do for 21

quaring a 2-digit number ending in 1
Take a 2-digit number ending in 1.
Subtract 1 from the numvber.
Square the difference.
Add the difference twice to its square.
Add 1.
Example:
1. If the number is 11, subtract 1: 11 - 1 = 10.
2. 10 × 10 = 100 (square the difference).
3. 100 + 10 + 10 = 120 (add the difference twice to its square).
4. 120 + 1 = 121 (add 1).
5. So 11 × 11 = 121.

Squaring a 2-digit number ending in 1
Take a 2-digit number ending in 1.
Subtract 1 from the numvber.
Square the difference.
Add the difference twice to its square.
Add 1.
Example:
1. If the number is 11, subtract 1: 11 - 1 = 10.
2. 10 × 10 = 100 (square the difference).
3. 100 + 10 + 10 = 120 (add the difference twice to its square).
4. 120 + 1 = 121 (add 1).
5. So 11 × 11 = 121.

Squaring a 2-digit number ending in 1
Take a 2-digit number ending in 1.
Subtract 1 from the numvber.
Square the difference.
Add the difference twice to its square.
Add 1.
Example:
1. If the number is 11, subtract 1: 11 - 1 = 10.
2. 10 × 10 = 100 (square the difference).
3. 100 + 10 + 10 = 120 (add the difference twice to its square).
4. 120 + 1 = 121 (add 1).
5. So 11 × 11 = 121.

@msrebeccablack I can't spell it till

@msrebeccablack hypteuse