A number is 65 when you subtract 6 then add 7. What is the number?

The problem can be modeled like this:

x - 6 + 7 = 65

x + 1 = 65

x = 64

The number is 64. Since - 6 + 7 = 1, you could have also simplified the question to, "A number is 65 when you add 1. What is the number?"