SWBAT use sequences and series to model financial scenarios.

Show me the money! Allow students to engage in a productive struggle with the geometric series formula by using it to model various financial situations like car loans, interest bearing accounts, and periodic savings.

80 minutes

Before students get back into the groups assigned in the previous period, I take a few minutes to hold a whole-group discussion about their progress so far. I make sure every group is clear on the expectations for a complete problem solving demo, which must be submitted at the beginning of the next class period. The demo should include a clear explanation of their problem-solving technique. [MP3] The posters submitted will go on the wall and any videos created by students will be played in class the following day.

Students then spend 80 minutes completing their problem-solving demonstration [MP1]. As they continue their work, I meet with each group to make sure they are on track. I offer more hints on day two than I did on day one, because I want to make sure they are able to complete the project and come up with a meaningful demonstration of their problem solving ability. During this time I also encourage the higher-ability groups to select the more challenging problems to present.

10 minutes

To complete the exit ticket, students must calculate the balance on two different interest-bearing accounts: one in which regular deposits are made and one in which a one-time deposit is made. This allows me to determine whether students have learned to differentiate among money problems that are modeled as sequences and those that are modeled as geometric series.

The homework, saving money problems, is a collection of mixed financial problems - some are best modeled as sequences and others as series. [MP4] I publish the answers to this assignment on Edmodo so that students will know whether they understand this material before tomorrow's assessment.