Finding the Square of a Number

 Finding square of a number 

Tips to solve it faster

Grade 6, 7, 8, Competitive Exams

If we have to find the square of a number that is more than 10 the conventional way is to multiply the number by itself as shown below : 

                                                                                                                                             Working is that first 28 is multiplied by 8 . So 8 x 8 is 64 and we write 4 in the units place and carryover 6..now multiply 2x8 which is 16 and add 6 to it so we have the answer as 224.

Now we multiply 28 by 2. We start writing the number from the 100’s place as 2 is in the 100’s place

Let’s see if we can find the square of a number in an easy way without doing much of calculation. Let’s take the number 34

Find the square of the unit number which is 4. Keep the unit digit. 1 will be carry over.

For the middle box multiply the digits of the number 3, 4 and the exponent (which is 2), then add 1 to the number that you get 1 was a carry over. Keep 5 and take 2 as carry over. Now find the square of 3 i.e

3x3 =9 then add 2 to it which was a carryover

So we have 9+2 =11

Now write the numbers as shown above which will be the answer

So we have 34x34 = 1156.

This method is based on the formula (A+B)^2= A^2 +2AB+B^2

Isn’t math Fun?

Try the worksheet attached  now