Square Root Tricks.

For finding square root of complete squares, we must memorize the squares of numbers 1 to 9.

Squares of 1 and 9 have 1 in the units place.

Squares of 2 and 8 have 4 in the units place.

Squares of 3 and 7 have 9 in the units place.

Squares of 4 and 6 have 6 in the units place.

Squares of 5 have 5 in the units place.

We use these facts to find square roots.

Find the square root of 784.

Divide the given number into two groups such that.

Tens and units digits are in one group.

Remaining digits are in the other group.

Two groups of 784 will be 7 and 84.

7 helps us to find the tens place digit of the square root.

7 lies between the squares 4 and 9.

Square root of smaller number 4, that is, 2 is the tens place digit of the square root.

The remaining group, that is, 84 helps us to find the units place digit of the square root.

Units place digit of 784 is 4.

For units place digit of the square root, there are two possibilities, 2 and 8.

Choose the correct digit out of 2 and 8.

Multiply the tens place digit of the square root, that is, 2 by its successor 3.

2 into 3 is equal to 6.

7 is greater than 6.

Thus, choose the greater of 2 and 8.

Therefore square root of 784 is 28.

Let us take another example.

Find the square root of 1849.

Its two groups are 18 and 49.

18 lies between 16 and 25.

Thus, tens place digit is 4.

Units place digit is either 3 or 7.

Now, 4 into 5 is equal to 20 and 18 is less than 20.

Therefore, smaller of the two, that is, 3 is the units place digit.

Therefore, square root of 1849 is 43.

The End.

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