Using Lux Blox, I’ve constructed a Christmas tree. As ornaments, I’ve attached gears of different sizes. In the first part of this video, the two gears are the same size and have a 1:1 gear ratio. This means that I only have to turn the driver gear one full rotation for the the driven gear to also make a full rotation. This is not the case for the second pair of gears. The driver gear has 11 teeth and the driven gear has 16 teeth. After about three full turns of the driver gear, the arrows nearly line up again, but not perfectly. These two gears have a different gear ratio than the initial pair.
Students can calculate for gear ratios by combining different gear combinations. If you’d like to try this activity outside of the holiday season, simply make a map that’s a different shape than a Christmas tree.