Table of Contents
- Long Division Method
- What’s Next?
In the previous segment, we learnt about the prime factorisation method to find square roots. In this segment, we will learn about the long division method.
How to find the square root of a number by long division?
The long division method is used to find the square root of large numbers usually. Let us understand the steps in this method by finding the square root of 8281.
Step 1: Write the division as shown below:
Step 2: Mark pairs of digits from the units end. Here, the pairs are 81 and 82.
Step 3: Find a perfect square equal to or just lower than the first pair from the left. Write the square root of this number to the left.
Here, the first pair is 82.
The perfect square lower and closest to 82 is 81.
92 = 81.
So, write the number 9 to the left of 8281.
Step 4: Multiply above and add below the same number.
Multiply 9 with 9 and write the product, that is 81, below 82. Add 9 with 9 and write the sum, that is 18, on the left side.
Step 5: Draw a box next to the sum. Subtract the product from the number above it. Here, draw a box next to 18 and subtract 81 from 82. This gives 1.
Step 6: Bring the next pair down.
The next pair is 81. Bring it down and write it next to 1.
