• Click on the arrow button in the figure to start the animation.
• The button will change to a "pause" button, which can be used to halt the animation.
  Notice how the point on the graph is paired with the points and arrow on the mapping diagram.
  
• Move the slider to change the value of $m$ or $b$.
• Check the box to see a second point and the related arrow on the mapping diagram and triangle on the graph that illustrates the "slope" of the line and the rate of change on the mapping diagram.
• Select the point $x$ in the mapping diagram to move the point by mouse or use the scroll up or down key  to move by increments of 1.
  

Martin Flashman, Sept 24, 2013, Created with GeoGebra