This method is to find square of the numbers which has unit’s digit as 5. i.e.: 25, 45, 65, etc.

You can find square of these numbers by three easy steps.

Step 1: Multiply ten’s digit with its next number.

Step 2: Find square of unit’s digit. i.e.: Square of 5.

Step 3: Write answers of step 1 and step 2 to together or side by side.

Let’s take examples.

## Find square of 35

Step 1: Multiply ten’s digit with its next number.

3 × ( 3 + 1 ) = 3 × 4 = 12

Step 2: Find square of unit’s digit. i.e.: Square of 5.

Square of 5 = 25

Step 3: Write answers of step 1 and step 2 to together.

## Find square of 65

Step 1: Multiply ten’s digit with its next number.

6 × ( 6 + 1 ) = 6 × 7 = 42

Step 2: Find square of unit’s digit. i.e.: Square of 5.

Square of 5 = 25

Step 3: Write answers of step 1 and step 2 to together.

## Find square of 95

Step 1: Multiply ten’s digit with its next number.

9 × ( 9 + 1 ) = 9 × 10 = 90

Step 2: Find square of unit’s digit. i.e.: Square of 5.

Square of 5 = 25

Step 3: Write answers of step 1 and step 2 to together.

## Find square of 115

Step 1: Multiply ten’s digit with its next number.

11 × ( 11 + 1 ) = 11 × 12 = 132
(Note: We are taking whole 11 as a ten’s digit.)

Step 2: Find square of unit’s digit. i.e.: Square of 5.

Square of 5 = 25

Step 3: Write answers of step 1 and step 2 to together.

## Find square of 215

Step 1: Multiply ten’s digit with its next number.

21 × ( 21 + 1 ) = 21 × 22 = 462
(Note: We are taking whole 21 as a ten’s digit.)

Step 2: Find square of unit’s digit. i.e.: Square of 5.

Square of 5 = 25

Step 3: Write answers of step 1 and step 2 to together.