It is needed to find all of the factors of 10 if you need to find all of the options for 10. If you don’t because you are simply dividing a number into 10, then you may not need to find all of the factors. In a math problem, you will need to find all of the factors of a number like 10 if the question asks you to find the factors of that number. You can’t just find some of the factors of a number. If you need to find all of the factors of a number like 10, then divide all numbers below 10 into 10. If there is a remainder, then that number is not a factor.