If the number you are adding is negative, the car backs up!

-1 + -3 = -4

press the purple "play" button to start the car


Try it:

-6 + -2 =

-3 + -1 =

-2 + -5 =


It works when you are adding more than two numbers too!

What's the answer to this one?

2+4+1=

Yep!

2+4+1=7

Here it is on the number line:

a number line showing 2+4+1=7

Here it is with the car:

press the purple "play" button to start the car