Use the sliders to enter two numbers for which you would like to find common factors[br][br]Now drag the YELLOW dot on the horizontal axis[br][br]When the vertical coordinates of WHITE dots are BOTH integers - [br][br]the horizontal coordinate of the YELLOW dot is a common factor of your two numbers[br][color=#ff0000][i][b] [br]Why does this work?[br][br]What questions could/would you put to your students based on this applet?[/b][/i][/color]