Q&A #202

Graphing linear inequalities

T2T || FAQ || Ask T2T || Teachers' Lounge || Browse || Search || Thanks || About T2T

View entire discussion

From: Kathy Murry
To: Teacher2Teacher Service
Date: Apr 23, 1998 at 22:47:25
Subject: Graphing linear inequalities

A teacher in our district is deducting points from her students' inequality graphs 
such as x>1 if the student does not darken the number line all the way to the end 
of the arrow that is drawn on the given number line. I have always allowed my 
students to draw a darkened arrow that points in the correct direction but have 
allowed their arrows to either be shorter than the given number line or even 
longer than the given number line. 

Her argument for deducting points is that every book shows the arrow ending 
exactly where the number line arrow ends. I have not found any books that aren't 
as she says. 

My argument is that the number line is a portion of the cartesian coordinate plane 
and has no end, so as long as the arrow is pointing in the correct direction, it 
indicates that the line continues in that direction and is a correct solution. 

Have I been wrong all of these years?

Post a public discussion message
Ask Teacher2Teacher a new question

[Privacy Policy] [Terms of Use]

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

Teacher2Teacher - T2T ®
© 1994- Drexel University. All rights reserved.
The Math Forum is a research and educational enterprise of the Drexel School of Education.The Math Forum is a research and educational enterprise of the Drexel University School of Education.