Let’s do this by example

Square root of 17.64 by long division

50.jpg

 

Therefore,

Square root of 17.64 = 4.2

 

Individual Steps are explained

 

Step 1:

  • Write the number
  • We make pairs from right.

For numbers before decimal point,

we start from right and make pairs

So, 17 is a pair

For numbers after decimal point,

we start from the right of decimal point and make pairs

So, 64 is a pair

51.jpg

 

Step 2:

Now we find that number whose

square is less than or equal to 16.

3 × 3 = 9

4 × 4 = 16

5 × 5 = 25

Since 25 > 17, we use 4 × 4.

 

So writing 4 on left side & top.

& 16 below 17

Now we find remainder,

17 − 16 = 1

52.jpg

 

Step 3:

Since next is decimal point

We put a decimal point on top

52.jpg

 

Step 4

Pair 64 comes down

So, our number is now 164

53.jpg

 

Step 5

We multiply the number above by 2

& add a blank after it

So, we write 4 × 2 = 8

8 _

54.jpg

 

Step 6

Find a number which is less than

Or equal to 164

81 × 1 = 81

82 × 2 = 164

 

Since 82 × 2 = 164. We use that

 

Thus,

Square root of 17.64 = 4.2

 

55.jpg

 

Square root of 1.125 by long division

56.jpg

 

Therefore,

Square root of 1.125 = 1.060…

Here, we can find square root upto more decimal digits.

But, we stop at 3 digits after decimal point

  1. Chapter 6 Class 8 Squares and Square Roots
  2. Concept wise
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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.