Hi Guys
this is a simple technique I use for finding square root of numbers only
perfect squares through
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Technique No. 1:
If you can remember the squares of numbers up to 10 then you can find square root of numbers up to 10000. Keep a few things in mind and remember this.
If you can remember the squares of numbers up to 10 then you can find square root of numbers up to 10000. Keep a few things in mind and remember this.
10^2= 100
20^2= 400
30^2= 900
40^2= 1600
50^2= 2500
60^2= 3600
70^2= 4900
80^2= 6400
90^2= 8100
100^2= 10000
And the
next thing to remember is
If a number
end with 1 then its square root must end with 1 or 9 eg. The square root of
numbers like 81, 121, 441 end with 1 or 9. Let’s check the following table
first to understand.
Now we can
say that
Last Digit of Number

Last Digit of its Square Root


1

1 or 9

4

2 or 8

9

3 or 7

6

4 or 6

5

5

Just note these things down and we are set only the first time is a bit difficult then figure it out.
So let’s try to find the square root a figure 9801.
We can see that it is definitely between 90 and 100
Since 9801 end with 1 its square root must also end with 1 or 9
So it mus t be 91 or 99...
now just find the arithmetic mean of 10000 and 8100
(10000+8100)/2 = 9050
9801 is grater then 9050
in case, given figure is grater than arithmetic mean value then we'll take last digit which is grater. Here between 1 and 9, 9 is grater.
So square root of 9801 will be 99.
Since 9801 end with 1 its square root must also end with 1 or 9
So it mus t be 91 or 99...
now just find the arithmetic mean of 10000 and 8100
(10000+8100)/2 = 9050
9801 is grater then 9050
in case, given figure is grater than arithmetic mean value then we'll take last digit which is grater. Here between 1 and 9, 9 is grater.
So square root of 9801 will be 99.
Technique No. 2:
To solve square root related problems in 3 minutes just watch following video: