Tuesday, 15 October 2019

Square And Square Root Shortcut Tricks

Square And Square Root Shortcut Tricks


Square and Square Root of two digit get using formula1


Square and Square Root get using formula


Formula: (a+b)2 = a2+2ab+b2 i.e, (a / b)2= a2 / 2ab / b2
we applied this formula to obtain the square of a number


Example 1:
( 57 )2


= ( 5 / 7 )2
Answer :
Apply formula of a2+2ab+b2
Consider,
572 = ?
A as 5
B as 7 (we break the number in two parts i.e, A as 5 and B as 7 and applied formula )
= 52 / 2 x 5 x 7 / 72
= 25 / 2 x 5 x 7 / 49
a2= 25
b2= 49
2ab = 2 x 5 x 7 = 70
= 25 / 70 / 49
 


Step 1: Put down 9 carry 4
 


Step 2: add carry 4 to 70 = 74 put down 4 carry 7
 


Step 3: add carry 7 to 25 = 32 put down 32
and answer is 3249,
= 3249


All this do on your mind which will help in fast calculation to obtain the answer of Square and Square Root of a number.
we applied this formula to obtain the square of a number


 


This is similar to the above Example.


 


Example 2:
(69)2
= (6/9)2
Answer :
Consider A as 6, and B as 9.
= 62 / 2 x 6 x 9 / 92
= 36 / 2 x 6 x 9 / 81 (we break the number in two parts i.e, A as 6 and B as 9 and applied formula )
a2 = 36
b2= 81
2ab = 2 x 6 x 9 = 108
=36 / 108 / 81


Step1: put down 1 carry 8
 


Step2 : add 8 to 108 =116 then put down 6 carry 11


Step3 : and add 11 to 36 = 47 and put down 47
= so answer is 4761,
= 4761



Note: All this do on your mind which will help in fast calculation to obtain the answer of Square and Square Root of a number.


 


Square and Square Root of three digit get using formula1


we applied this formula to obtain the square of three digit number
 


Example 1:
 


Square and Square Root of 1142


Answer :
Firstly we separate the 114 like this (11/4)2
then applied previous formula on it


=112 / 2x11x4 / 42
=112 / 2x11x4 / 16
=121 / 88 / 16
=12996
we apply the formula a2 + 2.a.b + b2
 


Step 1: note down 6 carry 1
 


Step 2: add carry 1 to 88 =  89, note down 9 carry 8.
 


Step 3: add carry 8 to 121 and note down 129
= 12996

Note: we can also separate 114 to find square like (1/14)2


 


Example 2:
 


Square and Square Root of 2232


Answer :
Firstly we separate the 223 like this(22/3)2


then applied previous formula on it
we apply the formula a2 + 2.a.b + b2
= 222 + 2 x 22 x 3 + 32
=484 / 132 / 9
= 49729


Step 1: note down 9
 


Step 2:note down 2 carry 13.
 


Step 3:add carry 13 to 4 = 17, note down 7
 


Step 4: add carry 1to 48 = 49 put down


= 49729


 


Note: All this do on your mind which will help in fast calculation to obtain the answer of Square and Square Root of a number.


 


Square and Square Root of 100 base method


Example 1: 982= ?
Answer :
 


Step 1: First we know that 982 is double of 98 that is = 98 x 98 = ?,
At first we count the number of less from 100. that is the above 98 is 2 less from 100.
 


Step2: Now we are going to multiply 2 x 2 = 4 and note down this 4 ( that are come from both less 98 x 98 from 100).
 


Step 2: put one Zero left from 4 and now subtract the less number is 2 from 98 that is = 96and the answer is 9604.


 


Example 2 : 962 = ?
Answer :
 


Step 1: First we know that 962 is double of 96 that is = 96 x 96 = ?,
At first we count the number of less from 100. that is the above 96 is 4 less from 100.
 


Step 2: Now we are going to multiply 4 x 4= 16 and note down this 16 ( that are come from both less 96 x 96 from 100).
 


Step 3: now subtract the less number is 4 from 96 that is = 92 and put down it
that is 9261


and the answer is 9216.


 


Square and Square root a number ending in 6


 


Example 1:
762
 


Step 1:put down 6
 


Step 2:Multiply 2 with (7 + 1) = 16 and add 16 +1 = 17.put down 7 and carry 1 .
 


Step 3:Multiply 7 with (7 + 1) = 56 + carry 1 = 57 put down 57
Answer is 5776


 


Example 2:
962
 


Step 1:put down 6
 


Step 2:Multiply 2 with (9 + 1) = 20 and add 20 + 1 = 21.put down 1 and carry 2 .
 


Step 3:Multiply 9 with (9 + 1) = 90 + carry 2 = 92 put down 92
Answer is 9216


 


Example 3:
362
 


Step 1:put down
 


Step 2:Multiply 2 with (3 + 1) = 8 and add 8 +1 = 9.put down 9.
 


Step 3:Multiply 3 with (3 + 1) = 12 put down 12
Answer is 1296


 


Example 4:
562
 


Step 1:put down 6
 


Step 2:Multiply 2 with (5 + 1) = 12 and add 12 +1 = 13.put down 3 and carry 1 .
 


Step 3:Multiply 5 with (5 + 1) = 30 + carry 1 = 31 put down 31
Answer is 3136


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