Comes After

This equation lets you choose a number and then see what follows that number. We're using counting integers here:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ...

For example:   Enter the number 5. 

What comes next?  The number 6 will be displayed.

This will work with negative numbers too, if you're a math wizard!