Some teachers require each student to purchase or create their own Captur paddle, while other teachers buy or create a class set that they use in every class. A teacher griped that some of his students weren't handing their Captur paddles back at the end of the class, so his supply of paddles was running low. He asked, "What should I do?"

Can't the students see the backs of the other students' paddles when they're giving their answers?