Cookie Monster

How it works

Cookie Monster has a set of jars. The first jar has one cookie, the second jar has two cookies, the third jar has three cookies, and so on. Cookie Monster wants to take all the cookies out of the jars so he can eat them, but there’s a rule he has to follow: Each round, he can take cookies from whatever jars he wants, but he has to take the same number of cookies from all the jars he’s taking cookies from.

In this activity, students start by trying to empty 3 jars in as few rounds as possible, then move on to more and more jars, with the goal of ultimately figuring out the minimum number of rounds they need to empty 100 jars.

Cookie Monster intro handout

Cookie Coloring handout

Different Distributions handout

Why we like this activity

• It’s fun! Students enjoy the challenge of trying to take all the cookies in as few rounds as possible.

• It helps students develop algorithmic reasoning.

• It requires students to engage in mathematical habits of mind:

  • Finding and using strategies to remove all the cookies from a set of jars in as few rounds as possible.
  • Comparing and contrasting strategies for removing all the cookies from different numbers of jars.
  • Looking for patterns in the relationship between the number of jars and the number of rounds it takes to remove all the cookies.
  • Making and testing predictions about how many rounds it will take to remove all the cookies from a specific set of jars.
  • Understanding and explaining how to remove all the cookies from a specific set of jars in as few rounds as possible.

• It has a low floor and a high ceiling: Students can start by using trial and error, but as the number of jars increases, students need to develop a more strategic approach.

Learn more about our approach to math and math education