SQUARE ROOT TIPS AND TRICKS
First we will have to remember this table
Number
|
Square
|
Last Digit
|
0
|
0
|
0
|
1
|
1
|
1
|
2
|
4
|
4
|
3
|
9
|
9
|
4
|
16
|
6
|
5
|
25
|
5
|
6
|
36
|
6
|
7
|
49
|
9
|
8
|
64
|
4
|
9
|
81
|
1
|
The last digits for the squares of 1 and 9 are both 1.
The last digits for the squares of 2 and 8 are both 4.
The last digits for the squares of 3 and 7 are both 9.
The last digits for the squares of 4 and 6 are both 6.
Now suppose we want to find the square root of 3249
Step-1 : Ignore the last two digit i.e 49
Consider only 32
Now 5^2=25 will be the number which is close to 32 because 6^2=36 is greater than 25
Right digit of square root will be 5
Step-2 ; Now Consider last digit of given number i.e 9
So left digit of our result will be either 3 or 7.
Step-3 : Now how to confirm whether it will be 3 or 7.
To confirm it just add 1 to result which we got in step-1 i.e 5
5+1=6
Now multiply these two number i.e 5 and 6
5*6=30 which less then left part of given number i.e 3249
So from 3 and 7 , we will consider the greater number i.e 7
Step- 4 : So final answer will be 57
Note : if multiplication of result and result+1 is greater than the left part of the given number then we will have to consider the smaller one from two number as in above example we consider 7 from 3 and 7 because multiplication i.e 30 was less than left part i.e 32.