Explanation

If we divide ‘78925’ by ‘87’ then we get:
\left(78925\div87\right)
\rightarrow 907 as a quotient and 16 as a remainder.
So, 16 is the least number.
Ans: 16 is the least number which must be subtracted from 78925 to make it exactly divisible by 87.

Other ways to ask this same question are:

1. How to find the minimum subtraction from 78925 to make it divisible by 87?
2. What is the least subtraction needed from 78925 to ensure divisibility by 87?
3. Finding the minimum number to subtract from 78925 for it to be divisible by 87.