When Chuck moved from Senior Faculty Status to Professor Emeritus, he gave up his last teaching related duty: conducting summer research with Grinnell students. This was an activity he began in 1992, and in the following years he worked with a total of 39 students.
Chuck investigates problems in geometric configurations. Examples of problem categories include: equidissections, tilings by polyominoes, dissections of rectangles into rectangular elements, fittings and coverings, equisum sets of points, Erdos sets of points. His current work is in equidissections, where he is attempting to extend some results published in a joint paper with Paul Monsky in 2008.