Just back the car up for negative numbers. 

-3 + -1 + -2 =

press the purple "play" button to start the car

Here it is on the number line:

a number line showing -3 + -1 + -2 = -6

-3 + -1 + -2 = -6


Your turn:

-5 + -2 + -1 =

-3 + -4 + -6 =