Divisibility by 25
100 is divisible by 25.
Therefore, every number that ends in two zeros is divisible by 25
For example: 300, 600, 700, 800, 5000, 9000
Let us consider numbers that do not end in zeros, for instance 8375 or 8345.
We can always represent such numbers as a sum of two numbers, one
of which ends with two zeros. For example, 8375 = 8300 + 75 and 8345 =
8300 + 45
In the first sum both numbers 8300 and 75 are divisible by 25, therefore their sum, 8375, is also divisible by 25. On the contrary, in the second sum one of the numbers (45) is not exactly divisible by 25, hence the sum, 8345, is also not divisible by 25.
A number is divisible by 25 if its last two digits are zeros or make a number divisible by 25.
For example: 800, 1100, 34000, 5275, 12825, 14350 are divisible by 25
355, 8640, 12395 are not divisible by 25