First choose a grid size by typing ’10’, ‘5’ or ‘2.5’. A randomly-placed grid of that size lat/long will be placed on the map (so if you choose ’10’ the grid width and height will be 10 degrees). Then, double click on the grid square with the highest population within it (based on US census tract information). The highest-population remaining square will give you 100 points, all the way down to 0 for the one with the smallest population. Try to obtain the most points by successively double-clicking on the highest-populated grid square.