**Previous Knowledge:** Walking the

line with the CBR and writing the

equation of a

line in

point slope form.

**Objective:** Students will work in groups of three and will be able to write the

equation of the

line for each interval from a

graph that they produce on the ranger. They will write a story to coincide with their graph. They will then swap with another group who will have to reproduce the

graph from the story and find the equations of the line.

**Materials:** CBR, TI-83, and

graph paper

**Group Size:** Three

**Procedure:**- Students should walk off a graph using the CBR. They should have a minimum of 2 intervals with positive slopes, 2 intervals with negative slopes, and 1 interval with a zero slope.

- Students should copy the graph from their calculator window onto a sheet of graph paper.

- Students need to find the equation of the line for each interval and write the equations on the graph paper.

- Students should then write a story on a separate sheet of paper to match their graph. Students should be encouraged to be creative and accurate.

- Each group will swap stories with another group.

- Each group will read the new story and walk the line on the CBR.

- They will then copy the graph from the calculator onto a piece of graph paper and find the equation of the lines on each of the intervals and write the equations on the graph paper.

- When the groups are finished, they will check their results with the original group.