Guest

Squaring numbers in the 20s Square the last digit (keep the carry) _ _ X Multiply the last digit by 4, add the carry _ X _ The first digit will be 4 plus the carry: X _ _ Example: If the number to be squared is 24: Square the last digit (keep the carry): 4 × 4 = 16 (keep 1) _ _ 6 Multiply the last digit by 4, add the carry: 4 × 4 = 16, 16 + 1 = 17 _ 7 _ The first digit will be 4 plus the carry: 4 (+ carry): 4 + 1 = 5 5 _ _ So 24 × 24 = 576. See the pattern? If the number to be squared is 26: Square the last digit (keep the carry): 6 × 6 = 36 (keep 3) _ _ 6 Multiply the last digit by 4, add the carry: 4 × 6 = 24, 24 + 3 = 27 (keep 2) _ 7 _ The first digit will be 4 plus the carry: 4 (+ carry): 4 + 2 = 6 6 _ _. So 26 × 26 = 676.

Squaring numbers in the 20s
Square the last digit (keep the carry) _ _ X
Multiply the last digit by 4, add the carry _ X _
The first digit will be 4 plus the carry: X _ _

Example:
If the number to be squared is 24:
Square the last digit (keep the carry):
4 × 4 = 16 (keep 1) _ _ 6
Multiply the last digit by 4, add the carry:
4 × 4 = 16, 16 + 1 = 17 _ 7 _
The first digit will be 4 plus the carry:
4 (+ carry): 4 + 1 = 5 5 _ _
So 24 × 24 = 576.

See the pattern?
If the number to be squared is 26:
Square the last digit (keep the carry):
6 × 6 = 36 (keep 3) _ _ 6
Multiply the last digit by 4, add the carry:
4 × 6 = 24, 24 + 3 = 27 (keep 2) _ 7 _
The first digit will be 4 plus the carry:
4 (+ carry): 4 + 2 = 6 6 _ _.
So 26 × 26 = 676.

Grade:12

1 Answers

Sourabh Singh IIT Patna
askIITians Faculty 2104 Points
7 years ago
Hii
Thanks for the info but seriously I was expecting a question . If in future you have queries do ask it on over here . We will surely help you out

Think You Can Provide A Better Answer ?

ASK QUESTION

Get your questions answered by the expert for free