One of the things my students this year are struggling with is appropriate scaling of graphs or number lines. One activity that has led to great discussions is this:
Label the Number Line so that you can accurately graph the following numbers:
This has lead to some great discussions about how they can fit all of these on such a small number line. Typically I do not start out with decimals, but Integers. As students get more comfortable with using scales and justifying why they placed a point at a certain location on the number line, I get into tenths, hundredths and even thousandths (for those groups who really want the challenge!) I generate my numbers using the tool from Meridian Outpost.
To check how accurate they are, I will have the numbers graphed on a larger number line, I’ll throw up a student graph on the SmartBoard, and “shrink” my line using the stretch/skew options. We then compare how close the two are. Students are very critical of each others work, and typically I sit back and allow student discussion to drive proper scaling and placement.
MathLab 