1-2b Modeling Subtraction

Take some time to experiment with the interactive number line below to model subtraction problems. Begin by dragging the red point to set the initial value, then drag the blue point to define the value you wish to subtract from the first value. The subtraction expression will automatically update, and you can use the selection box to view the solution. Experiment with the interactive until you can answer the following questions:
  • What does the subtraction of a positive number look like on the number line?
  • What does the subtraction of a negative number look like on the number line?
  • How does the subtraction problem look different from the addition problem? Could you write the subtraction problem as addition?