When we go out to eat at a restaurant, it’s customary to tip as a percent of the bill. What this means, though, is that the tip doesn't depend on how hard the server works, but how expensive the menu is.
In this lesson students will use mental math to quickly estimate tips – 10%, 15% and 20% – at various restaurants. As they do, they’ll realize that the pricier the food, the larger the tip. Students discuss whether they think this is fair, and come up with alternative methods of tipping.