Tests for Divisibility of Numbers - Divisibility by 10

If a number has 0 in the one's place, then the number is clearly divisible by 10.

Example:
Is the number 1234567890 divisible by 10?
Check for the unit digit; it is 0.
So 1234567890 is divisible by 10.

Explanation for Divisibility by 10:
Take the number... cba; this is a short form for ... + 100c + 10b + a
Here, a is the one’s digit, b is the ten’s digit, c is the hundred’s digit, and so on.
The dots are there to say that there may be more digits to the left of c.
Since 10, 100,... are divisible by 10, so are 10b, 100c, ...
As for the number, as it is concerned, it must be divisible by 10 if the given number is divisible by 10. This condition is possible only when a = 0.
Hence, a number is divisible by 10 when its one’s digit is 0.