Count up to 120

Suppose Annie counted from 113 to 119. 

Let's identify the numbers she counted.

Start with 113 and count forward to 119.
 

113, 114, 115, 116, 117, 118, 119
 

Now, count the numbers Annie counted.
 

6

So, Annie counted 7 numbers, which are 113, 114, 115, 116, 117, 118, 119.