Square any two digit number:
Suppose the number is 47
Look for the nearest multiple of 10
Example:
The nearest number is 50. We will reach 50 if we add 3 to 47
So multiply (47+3) x (47-3) = 50 × 44 = 2200 This is the 1st interim answer.
We had added 3 to reach the nearest multiple of 10 that is 50 thus 3x 3 = 9 This is the second interim answer.
The final answer is 2200 + 9 = 2209
Multiply any two numbers from 11 to 20 in Easy Way:
Example:
Take 15 × 13
Take the larger no on the top and the second digit of the smaller no. in the bottom.
15
3
Add 15+3 = 18 . Then multiply 18 × 10 = 180
Now multiply the second digit of both the no.s (ie; 5 × 3 = 15) Now add 180 + 15.
Here is the answer 180 + 15 = 195
This is a simple trick. It will help you a lot.
Multiply any two digit number with 11:
Example:
27 × 11
Divide the number as 2 _ 7
Add 2 + 7 = 9
Thus the answer is 2 9 7
But there is one complication. If you take a number like 57 Thus 5_7 x 11
Divide the number as 5 _ 7
Add 5 + 7 = 12
Now add 1 to 5 and place 2 in the middle so the answer is 5+1_2 _7 = _627
Thus the answer is 627.
Square a two digit number ending in Five:
Let the number be 35
35 × 35
Multiply the last digits of both the numbers 5 × 5 = 25
now add 1 to 3 thus 3 + 1 = 4
multiply 4 × 3 = 12
thus answer 1225
You will have to think over this one carefully.As 5 has to come in the end so the last two digits o the answer will be 25 . Add 1 to the first digit and multiply it by the original first digit . Now this answer forms the digits before the 25. Thus we get an answer.
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