The data from a survey of high school math and science teachers show that in the district of Sanlee many of these teachers reported assigning daily homework, whereas in the district of Marlee, most science and math teachers reported assigning homework no more than two or three days per week. Despite receiving less frequent homework assignments, Marlee students earn better grades overall and are less likely to be required to repeat a year of school than are students in Sanlee. These results call into question the usefulness of frequent homework assignments. Most likely the Marlee students have more time to concentrate on individual assignments than do the Sanlee students who have homework every day. Therefore teachers in our high schools should assign homework no more than twice a week.