You will be shown 10 different circles of radius 25-200 miles. Using the slider (or manually typing into the box below the slider), guess the population contained within each circle then click SUBMIT for each one. Populations are based on the portion of 80K+ US Census Tracts contained within the circle. Canada and Mexico populations are NOT counted toward the total.

The object of this quiz is to place 20 circles of radius 100 miles on the map so that they contain the largest total population.

When you begin you'll be given a 100-mile radius circle centered on the map. Move it using the mouse and click SUBMIT. You will be given a score for that circle corresponding to the total population among all US census tracts within it (there are about 85K total US census tracts averaging about 4K people each). Try to complete all 20 circles with the highest total score.

Any INTERSECTING areas are only counted one time, so no census tract will be counted more than once.

The object of this quiz is to place 10 circles of radius 100 miles on the map so that they contain the largest total population.

When you begin you'll be given a 100-mile radius circle centered on the map. Move it using the mouse and click SUBMIT. You will be given a score for that circle corresponding to the total population among all US census tracts within it (there are about 85K total US census tracts averaging about 4K people each). Try to complete all 10 circles with the highest total score.

Any INTERSECTING areas are only counted one time, so no census tract will be counted more than once.