How to findSquares of Numbers ending in 5

in less than 3 seconds?

352 452 852 etc.

Lets take for example

35

35x

Here we see that

35

35x

That the Units place adds upto 5+5 = 10 and that the Ten’s place is same.

When this is true what we do is

35

35x

Apply the Word Formulae ‘ By one more than the One before” to the ten’s place.

So Whats 1 more than 3?. It is 4. So we multiply 3 with 4 to get 12. That’s the first part

of our answer.

12

To get the second part of our answer

35

35x

We multiply 5 with 5 to get 25. That’s the second part of our answer.

So our answer becomes 1225.

1225

Now try

85

85x

Solution

85

85x

7225 We multiply 5 with 5 to get 25. And multiply 8

with the next number 9 to get 72. So our answer becomes 7225. Simple.

Now try 452 552 652 952 1052 1252 etc.

in the same way.

Now what do we do for these sums?

26

24x

48

42x

67

63x

Now what do we do for these sums?

26

24x

48

42x

67

63x

Note that the units add upto 10 and the tens place is same.

So we can apply the same rule “ By one more than

the One before” . Lets see what we get.

26

24x

48

42x

67

63x

26

24x

48

42x

67

63x

6|24 20|16 42|21In 48 x 42 we have 4 multiplied with the next number 5 which gives us 20 and 8 x2 which

gives us 16. Therefore our answer 2016. Similarly try the other sums.