My high school business teacher gave everyone in the class one of these little cards. I think it was supposed to help us save face at business lunches or something so we wouldn't under tip. It bothers me more to think if I am paying for a meal that someone is watching me fill out that section of the receipt! I usually calculate tips in my head which doesn't seem very hard and I am extremely math averse! If I were still struggling, I would use the calculator on my cell phone.