Question

square root short trick

Answer 1

How to Find Square Root of a Four Digit Number

Let’s learn how to find square root by taking different examples.

Example: Find the square root of 4489.

We group the last pair of digits, and the rest of the digits together.

Now, since the unit digit of 4489 is 9. So we can say that unit digit of its square root will be either 3 or 7.

Now consider first two digits i.e. 44. Since 44 comes in between the squares of 6 and 7 (i.e. 62 < 44 < 72), so we can definitely say that the ten’s digit of the square root of 4489 will be 6. So far, we can say that the square root will be either 63 or 67.

Now we will find the exact unit digit.

To find the exact unit digit, we consider the ten’s digit i.e. 6 and the next term i.e. 7.

Multiply these two terms

sqrt3

Since, 44 is greater than 42. So square root of 4489 will be the bigger of the two options i.e. 67.

Let us take another example.

Example: What is the square root of 7056?

sqrt4

Unit digit will be 4 or 6.

Since, 82 < 70 < 92

So the square root will be either 84 or 86.

Now consider 8 and 9

sqrt5

Since, 70 is less than 72. So square root will be the lesser of the two values i.e. 84.