If a number is divisible by 3, that means that 3 goes into it without leaving a remainder. For example, 3 goes into 6 twice, exactly, but 3 goes into 7 with 1 remainder. So 6 is divisible by 3, but 7 isn't.
How many of the numbers 1-12 are divisible by 3? (1 isn't, 2 isn't, 3 is. 4 isn't, 5 isn't, 6 is. etc.)
[3,6,9,12 are divisible, so 4 of them]
How many numbers are there in total, from 1-12?
[12]
Your answer is those two numbers as a fraction.
[4/12] = 1/3
