Goofus is up to his old tricks again. He hasn't been paying attention in class, and he's missing all of the problems. Can your students help analyze his work, find his mistakes, and solve the problem correctly. Part of a series of What Went Wrong worksheets I've created, this is sure to help assess your students' ability to find the volume of rectangular prisms. I've also included a poster for display, as well as individual cards that can be passed out to students for pasting or taping into math notebooks/journals for easy reference.