The Math Forum

Chameleon Graphing

Sam's Home ||  Chameleon Home ||  Chameleon Graphing Java Applet ||  Ask Dr. Math

Chameleon Home
The Line
The Plane
For Grownups

Negative Numbers on a Line

So far, when Sam wanted to graph a point, he started at zero and went forward. What would happen if he wanted to go the other way? After all, there are lots of points before the one we labelled zero.

Let's label some more points, going backwards from zero. We'll use the "-" symbol to show that these numbers are less than zero.


The numbers before zero on the number line are called negative numbers. We read a number like -4 as "negative four."

Let's ask Sam to graph negative two.

    Sam always starts at zero.


    Sam knows he has to graph a negative number, so he turns around.


    He moves two units away from zero, because negative two is two less than zero.


    Finally, Sam marks the point he found with a big green dot.


Sam found -2.


Please send questions, comments, and suggestions
to Ursula Whitcher

[Privacy Policy] [Terms of Use]

Home || The Math Library || Quick Reference || Search || Help 

© 1994- The Math Forum at NCTM. All rights reserved.