Activity Link Description Grade   Choropleth Maps and Population Interactive Flash animation lesson exploring population change over time that helps students put trends into perspective, gather the right kind of data, and make choropleth maps that help develop critical thinking skills.   6-10 $tore Territory: Analyzing Retail Market Areas A set of interactive Flash animation scenarios that allow students to investigate the effect of strategies for locating franchises.  Students experiment with the variables of: minimizing travel distance, franchise territory division, maximizing market share, and simulated regions.   5-12 House Hunter for Area A hands-on activity you can do with fourth-graders to directly apply the concept of area to the place they knows best – their houses.   4 Stonehenge Geometry   Stonehenge builders had geometry skills to rival Pythagoras HS