Question

Q7. What will be the number of zeros in the square of 400 ?
( a) 5 ( b) 1 ( c ) 3 ( d ) 4

Answer 1

there will 4 zeros after doing sq of 400....
400sq=160000..

Answer 2

Given : The main number is 400

To find : The number of zeroes in the square of the main number.

Solution :

We can simply solve this mathematical problem by using the following mathematical process. (our goal is to calculate the number of zeroes in the square of the main number)

There's a technique by which we can simply solve this type of problem without any manual calculations. Usually a number having a certain number of zeroes at its end, will have double the number of zeroes at its end when squared.

Eg. 10 has 1 zero at its end, so its square (10² = 100) 100 has 2 zeroes at its end. (1 zero became 2 zeroes, when squared)

Similarly, 400 has 2 zeroes. So, in its square it will have 4 zeroes.

Verification :

• (400)² = 160000
• 160000 has 4 zeroes, as said before.

Hence, there will be 4 zeroes in the square of 400