This highly visual game is a favorite in my remedial math classes. The students are still working on their understanding of percentages, and this helps them to visualize what percentage really means.
Each slide has a unique pie chart created using Google Sheets. There are only two colors on each chart: teal and gray. Students first guess the teal percentage of the pie chart, then they use math to determine the gray percentage. With seven different pie charts, students are working to determine 14 different percentages.
I like to play this game as a warm-up for the class, as a little brain break, or just as something fun before, during, or after testing.
When students are guessing the teal color, I conduct a number talk of sorts before revealing the answer. I ask different students to explain how they came up with their answers in order to help other students develop similar strategies and to get my students talking. For example, many students will explain that they mentally divided the circle into quarters and then guessed based on where the teal fell around their quartered lines.
Students then need to do a little bit of math to determine what the remaining gray percentage is based on the correct answer for the teal. This helps to reinforce that percentages have to add up to 100. If teal is 20%, then the gray has to be 80%. This also usually helps all students to get some points even if they are struggling to guess the teal portion.