## Friday, August 24, 2012

### Save the Zogs

"Four frightened Zogs have left the safety of their planet and are floating around in space. The Duplicators, a band of space travelers with the ability to imitate others, have infiltrated the floating Zogs. This is making the rescue mission very difficult.

Fortunately, the Zogs are very clever. They can assemble themselves along a straight line path. The Duplicators cannot exist on this path. If the rescue team can determine the equation of this line, then the Zogs will be saved. The Duplicators will be left behind.

To rescue the Zogs, you need to learn as much as possible about linear equations and the lines they create. What happens when the slope is zero? What effect does the y intercept have on the position of the line? The more you know, the more Zogs you can save."

The game begins with simple horizontal and vertical lines, builds to equations with non-zero slopes passing through the origin, and ends with equations that have both non-zero slopes and y-intercepts. A tracking tool enables students to rotate and move a line into position to help them visualize whether or not the line passes through the correct Zogs. Once the visual is in place, students must then identify the equation the describes the line.

What middle school student can resist the plight of the Zogs?