Which letter on the number line represents 5 added to -4?

A) A
B) B
C) C
D) D

Start at -4 on the number line. Then move 5 units to the right to get to 1, which is where point C is located.

This shows -4+5 = 1 which is the same as saying 5+(-4) = 1 or 5-4 = 1.

Here's one real world application:

You are on basement level 4, meaning you are 4 floors below the ground floor. If you take the elevator up 5 floors, then you'll end up on the first floor of the building.

the one below it is a function