Atoy car is placed at 0 on a number line. it moves 9 cm to the left, then 4 cm to the right, and then 6 cm to the left. the total distance the toy car traveled is

The car traveled (9cm + 4cm + 6cm) = 19 cm .

But since it was going back and forth on the same line,
it ended up

                     (9cm + 6cm) left  +  (4 cm) right =

                             15cm left     +   4cm right  =

                                 11cm left of where it started out.