Numbers divisible by 5 end in 0 or 5.
A number's divisibility by 5 is easily determined by looking at its last digit. This stems from the base-10 number system we use. Any number can be expressed as a sum of multiples of powers of 10, plus the last digit. All powers of 10 are divisible by 5 (10, 100, 1000, etc.), so whether the whole number is divisible by 5 depends solely on whether the last digit is divisible by 5. Only 0 and 5 are divisible by 5.
Here are some examples:
- Numbers divisible by 5 (ending in 0): 10, 20, 100, 130, 250
- Numbers divisible by 5 (ending in 5): 5, 15, 25, 105, 345
- Numbers NOT divisible by 5: 1, 2, 3, 4, 6, 7, 8, 9, 11, 12, 13, 14, 16, etc.
It's worth noting that numbers divisible by 10 always end in 0 and are, therefore, always divisible by 5. However, not all numbers divisible by 5 are divisible by 10.
