Jon wrote a whole number ending in 5 zeros. If he multiplies the number by 100, how many zeros should be in the product?

8
5
2
7

1 answer

If Jon has a whole number that ends in 5 zeros, we can express that number as \( N = x \times 10^5 \), where \( x \) is some integer.

When Jon multiplies this number by 100, we need to calculate \( N \times 100 \):

\[ N \times 100 = (x \times 10^5) \times 100 = x \times 10^5 \times 10^2 = x \times 10^{5+2} = x \times 10^7 \]

The product \( N \times 100 \) clearly ends with 7 zeros (from \( 10^7 \)).

Thus, the number of zeros in the product is \( \boxed{7} \).