Stand Up and Be Counted

Today we worked in groups to complete the following problem solving activity:

Suppose a class of 32 seated students count off. Students who say an even number stand up. Once that is done, only the students still seated count off. Again, students who say an even number stand up.
• At the end of the second count-off, how many students are still seated?
• How many times will it take before everyone in the class is standing?
• How would the game change if students who say an odd number stand up and students who say an even number remain seated?

After working in small groups, we got back together as a large group to share the strategies that we used and our solutions.