 Let us see how the squares of numbers ending with five are done. So for example, if we want to square 35 There are two parts of the square One is the right hand side part which are the last two digits and these last two digits are always 2 and 5 Which is basically the square of 5 So this 25 comes from the squaring of 5 and rest of the earlier digits for the square of 35 come from multiplying this number by Its next number. So we add 1 to 3 and then we multiply that with the original number And that gives us 4 times 3 which is 12 and I can just fill it up. And so this is the square of 35 So we could just say 35 square is 1225 this method is known as a card became a poor winner. Let's just reinforce what we just studied Let's take one more example. So if we wanted to square 115 So the right hand side part is going to be 25 And then what we will do is that we will multiply 11 with 12 because 12 is the next number for 11 and the multiplication of 11 and 12 is 132 and we just put 132 on the left hand side of 25 and that is the square of 115. So basically 115 square Is 13225 Let us square 85 square of 5 is 25 that is being put on the right. Then we do 8 times 9 Which is 72 So this is the left hand side part. This is the right hand side part We just combine those and that is the square of 85