 I have a quick tip from Jeff that is, well, it also involves swiping, but it's a little bit different. He says, you probably know that if you enter a number incorrectly in the iPhone calculator, you can press C to cancel and re-enter the correct number. But did you know that you can simply erase a digit from the number you are currently entering by swiping left or right on the actual number you are entering at the time? You may want to remind listeners that rotating the iPhone sideways into landscape mode converts the iPhone calculator into a full scientific calculator, so that's two quick tips in one.