This is a great animated powerpoint that helps students visualize the addition and subtraction of integers on a number line. There are 12 practice problems (6 addition problems and 6 subtraction problems), with 2 slides for each problem. The first slide in each pair is the problem slide and shows only the problem, giving students a chance to figure out the answer on their own. The second slide is the answer slide and shows the problem and the answer, as well as an animated number line with colored bars that expand to illustrate the problem.
For example, for the problem -3+5=2, the problem slide will show -3+5= and the answer slide will show -3+5=2. The answer slide will also have a number line with a red bar labeled “-3” that expands from 0 to -3 and then a blue bar labeled “5” that expands from -3 to 2 and then a yellow answer bar that expands from 0 to 2, showing “2” as the answer.
All number lines are from -10 to 10, so the problems have numbers and answers in this range. For each subtraction problem, the answer slide shows how subtraction was changed to addition by adding the opposite.
There are a total of 27 slides (24 problem and answer slides and 3 title slides).
Click to advance the slides and click to start the animation on the answer slides.