When we talk about numbers that have 5 as a factor, we are referring to numbers that are divisible by 5. One important characteristic of such numbers is their ones place digit.
A number is divisibly specifically by 5 if its last digit (the ones place) is either 0 or 5. This is due to how our base-10 number system works.
- 0: When a number ends with 0, it is certainly divisible by 5. For instance, 10, 20, and 305 are all divisible by 5.
- 5: Similarly, if a number ends with 5, it is also divisible by 5. Examples include 5, 15, and 125.
Hence, the only possible digits that can be in the ones place of a number that has 5 as a factor are 0 and 5.