Frog Stretcher/Shrinker

Multiplication as Scaling

This applet demonstrates how multipication is stretching or shrinking.
The quantity that is stretched or shrunk is the height of the green frog, standing at 1 on the horizontal axis. The result is the height of the red frog.

The amount to stretch is called the scale factor; change it by dragging the blue point S on the horizontal axis.)
Change the height of the original green frog by moving the point H on the frog's head up or down.

Questions to think about

What happens when the scale factor is greater than 1?
What happens when the scale factor is between 0 and 1?
What happens when the scale factor is negative?
What happens when the green frog's height is negative, for each of the three categories of scale factor above?

To see just the geometry, uncheck the Show frogs box.

Technical help

The last control button on the right moves the drawing pad, in case something is off the screen. There is a tiny triangle in the lower right of that button. Pull it down to see the other related tools, including zoom in and zoom out. The zoom's center is where you click with the zoom tool selected.

To reset the construction, click the arrow in the corner. Double click in the geometry window to open the full program for even more control.
For more control

Susan Addington, 11/21/11, Created with GeoGebra