The math department at my school is working to implement instructional routines in our classes for several reasons. The first reason is to increasingly apply the standards for mathematical practice on a daily basis. The second reason is to improve our communication as a department by creating common language centered around shared routines and activities.

One of the instructional routines we plan to implement is Contemplate then Calculate (#CthenC on twitter). Created by Amy Lucenta and Grace Kelemanik at the Boston Teacher Residency, #CthenC is a highly structured routine that simultaneously allows for open mathematical thinking and problem solving. Contemplate then Calculate highlights looking for and making use of mathematical structure in problem solving.

In an effort to assist the implementation of Contemplate then Calculate at our school, I created this activity to do with my class as a model for implementation and discussion.

Here is the task: