Will ran 3.23 km the first week and 4.15 km the second week. Chuck ran 8.75 km in two weeks. Round each distance Will and Chuck ran to the nearest tenth of a kilometer. Then estimate. About how much farther did Chuck run than Will?
Well, if you add the two distances for Will first (3.23 and 4.15) then round the sum (3.23+4.15=7.38=7.4), then round Chuck's total (8.75=8.8), then subtract Will's total from Chuck's (8.8-7.4), you get 1.4km.
