The sum of three consecutive numbers is 117. what is the smallest of the three numbers?

When doing consecutive numbers you have to think about how you get to the next number when counting. If I start with 5, I have to add 1 to get to 6, and add 2 to get to 7. This is the same way we do this problem except we don't know the starting number so we use x.
x + (x + 1) + (x + 2) = 117 Combine like terms
3x + 3 = 117   subtract 3 from both sides
3x = 114         divide 3 on both sides
x = 38
x + 1 = 39
x + 2 = 40
The question wants the smallest number, x = 38