Hi Robert, I totally agree! I teach a Ten-key course, of course, which is math related. I have an exercise where mistakes have been made on an adding tape, and students must compare the adding tape to the actual problem to determine what mistake(s) was made on the adding tape. The studenst are to correct the mistakes without reworking the entire problem. There are many people who cannot find their own mistakes. They know something is wrong, but they do not know what is wrong or how to fix it. Using logics is a good way to catch math-related mistakes. Patricia