All-e Any time

Let’s consider the number 75 to find its square.

Start writing the answer of last two digits number that is 25 because any number that ends with 5 is 25

Take the first digit of the number 75. That is 7 and take the number that follows 7 is 8.

Now, multiply 7 and 8, we get the number 56.

Finally, write the number 56 in the prefix and combine with 25 what we already wrote.

So, the answer is 5625.

We can summarize this as an equation.

Squares Ending in 5:  n5 = n(n + 1)5² = n(n + 1)25 , where ‘n’ is the first digit.

Example: Let’s consider the number 75 to find its square. Here n = 7,

So, 75 = 7(7 + 1)25 = (7 x 8) 25  = 5625.