Just calculate the tip in your head! According to the book “Boost Your Brainpower In 60 Seconds,” using your phone’s tip calculator robs you of a chance to exercise your brain – the same way driving to a restaurant a mile from home robs you of the opportunity to exercise your body. And unless we reinforce simple mathematical skills, our brain will eliminate those neural connections because they’re not being used. Meaning, it really IS a case of use it or lose it. So the next time you’re out to eat, figure out the tip in your head to keep your brain sharp!