A Number Line (Plot) interaction presents a number line on which candidate may plot equalities and inequalities.
Here is an example of a Number Line (Plot) item:
The correct answer here is x > -8. The candidate must use the tools to draw this on the number line.
You may customize the number line to change the increments, add a title, or add an axis label. You may also choose to display only certain plotting tools.
Creating a Number Line (Plot) Interaction
- In the item editor, click the plus sign and click Stem. This displays the Select Interaction Type window.
- Click the Graphing tab to reveal graph-based interaction types.
- Select Number Line (Plot), then click Create Interaction.
- Add content to your stem prompt (ex: "Create a number line plot ...").
Customize the Number Line
You should begin by changing the appearance of the number line if the default appearance is not appropriate for your item. To do this, click Customize.
The Chart Editor appears.
Make changes using the options available. Click Update Chart Preview to see how the changes will look. For example, the "Min" value was changed to -10.5 in the image above.
When you are finished editing, click Close.
Indicate the Correct Plot
Next, draw the correct plot that you expect the candidate to draw. Use the drawing tools to draw on the number line. For example, to plot the correct answer for the example shown above:
Click the "Right Exclude" tool, which excludes the end point and extends to the right.
Click on the correct end point (which is -8 for the example shown above). A plot appears.
Erasing a Plot
If you need to erase a plot you created, click on the trash icon to delete the plot.
By default, the candidate receives 1 point for drawing the plot correctly, using the correct tool.
If you need a plot that displays on the number line but is not scored, choose "Background" as the type option within the scoring section.
The plot turns gray on the number line. You may optionally have a label on the plot.