As a review of fractions, I gave students several pizzas to create in the app Pizza Time! For instance, they had to create a pizza with sauce on 1/2 and cheese on 1/4. After creating each pizza, they emailed it to me. As a challenge for students who finished quickly, they had to pick one of the types of pizzas and show me as many ways to create that type of pizza as possible. I suggested they do some "tree" planning on paper first.