Number Line Operations with Task

In the app below, Drag the red and blue points to see how the number line and equation are related.
  1. What does the blue point show from the equation?
  2. What does the red point show from the equation?
  3. What do the "humps" show from the equation?
Use the number line to help you find the value of in each problem.
  1. 5 + = 12
  2. 8 + 6 =
  3. + 9 = 13
  4. 18 - 7 =
  5. 13 - = 7
  6. - 2 = 1