> Choose a number over 100 (START WITH SMALLER NUMBER).

> The last two places will be the square of

the last two digits (keep if any carry) _ _ _ X X.

> The first three places will be the number plus

the last two digits plus any carry: X X X _ _.

here is an Example:

> let the number be 108:

2. Square the last two digits (no carry): 8 × 8 = 64: _ _ _ 64

3. Add the last two digits to the number: 108 + 08= 116:

so 1 1 6 _ _

4. So 108 × 108 = 11664.

### square of numbers in 100's

Posted by
SHRENIK
on Wednesday, September 16, 2009

Labels:
SQUARE OF A NUMBER
/
Comments: (6)

### FIND SQUARE OF NUMBERS IN 200 TO 299

Posted by
SHRENIK

Labels:
FUN WITH NUMBERS,
SQUARE OF A NUMBER
/
Comments: (2)

steps to find square of numbers in 200's

> Choose a number in the 200s (start with numbers under 210, then try for larger ones).

>The first digit of the square is 4: 4 _ _ _ _

> The next two digits will be 4 times the last 2 digits: _ X X _ _

> The last two places will be the square of the last digit: _ _ _ X X

here we take an Example:

> let the number be 207:

> The first digit is 4

so 4 _ _ _ _

> The next two digits are 4 times the last digit:

4 × 7 = 28

so _ 2 8 _ _

Square the last digit: 7× 7 = 49

so _ _ _ 49

So finally we get 206 × 206 = 42849.

and For larger numbers work right to left:

> Square the last two digits (keep the carry): _ _ _ X X

> 4 times the last two digits + carry: _ X X _ _

> Square the first digit + carry: X _ _ _ _

example

>If the number to be squared is 225:

> Square last two digits (keep carry):

25x25 = 625 (keep 6): _ _ _ 2 5

> 4 times the last two digits + carry:

4x25 = 100; 100+6 = 106 (keep 1): _ 0 6 _ _

> Square the first digit + carry:

2x2 = 4; 4+1 = 5: 5 _ _ _ _

> So 225 × 225 = 50625.

> Choose a number in the 200s (start with numbers under 210, then try for larger ones).

>The first digit of the square is 4: 4 _ _ _ _

> The next two digits will be 4 times the last 2 digits: _ X X _ _

> The last two places will be the square of the last digit: _ _ _ X X

here we take an Example:

> let the number be 207:

> The first digit is 4

so 4 _ _ _ _

> The next two digits are 4 times the last digit:

4 × 7 = 28

so _ 2 8 _ _

Square the last digit: 7× 7 = 49

so _ _ _ 49

So finally we get 206 × 206 = 42849.

and For larger numbers work right to left:

> Square the last two digits (keep the carry): _ _ _ X X

> 4 times the last two digits + carry: _ X X _ _

> Square the first digit + carry: X _ _ _ _

example

>If the number to be squared is 225:

> Square last two digits (keep carry):

25x25 = 625 (keep 6): _ _ _ 2 5

> 4 times the last two digits + carry:

4x25 = 100; 100+6 = 106 (keep 1): _ 0 6 _ _

> Square the first digit + carry:

2x2 = 4; 4+1 = 5: 5 _ _ _ _

> So 225 × 225 = 50625.