Positive and Negative Rotating Number Line - Set of 10

Make the effect of adding and subtracting to positive and negative numbers clear to see with this transparent rotating number line. The stationary number line displays numbers -10 through 10, while the rotating arm is blank, allowing students to mark an integer to add or subtract from either side. Students can then swing the arm to literally see what the answer is.

To add or subtract a positive number, students will position the arm vertically above the number line. For negative numbers, students will position the arm vertically below the number line. For example, to see what 10 - 3 looks like, a student could put the arm in a vertical position above the number line, then count 3 lines down from the top and draw a dot with a dry-erase marker. The student can then swing the arm towards the positive side and match it up with the number line to see that 3 less than 10 is 7. Made of durable, write-on/wipe-off plastic. Set of 10.