This Math Monday, we’re exploring the custom Desmos activity from the Financial Algebra lesson FA-4.8 Constraints and Optimization.

The Lesson

Students work with complex systems of inequalities and practice finding optimal solutions when faced with numerous constraints. 

When working with multiple inequalities, some students have difficulty visualizing the solution set. That’s where Desmos comes in - the interactive graph and sketch features provide valuable support. 

The Desmos Activity

This Desmos Activity is one option for students completing Level 1 of the FA-4.8 Application (although they may choose to complete it on paper as well). 

First, students match equations with their graphs. The automatic tally of correct card pairs helps students check their work as they manage several equations. 

Then, students are introduced to the system they’ll work with for the rest of the Application. Given the first three inequalities, students use the interactive draggable points and buttons to graph the fourth. Again, automatic feedback will tell students - and you! - when they’ve completed each step correctly. 

Next, students use the sketch feature to identify the solution set.

Students then identify a solution to the system. But here’s the trick - they can see the solutions that their classmates have found, too! This reinforces students’ conceptual understanding of the solution set, since they can observe points clustered in the shaded area they just sketched. 

Finally, students answer a set of reflection questions about what these solutions represent in the real-world context of a business.

Where to Find NGPF’s Desmos Activities

You may be wondering where exactly you can find these great Desmos activities. 

If you’re using our Financial Algebra curriculum, Desmos Activity links are built directly into the lessons. You can find them in the Lesson Guides and Application Answer Keys. Note: Desmos activity links are teacher-facing, so will not be included in the Student Activity Packet and student-facing Application.

To look through NGPF’s library of Desmos activities, you can check out our Financial Algebra Collection.

Want More?

• Financial Algebra course page
• VPD: Financial Algebra: Budgeting and Systems of Inequalities; this Wednesday at 1 pm Pacific
• Stay tuned for our next Financial Algebra unit release!

Looking for another budgeting lesson about constraints? Check out LESSON: Case Study: How Do I Budget?

About the Author

Kathryn Dawson

Kathryn (she/her) is excited to join the NGPF team after 9 years of experience in education as a mentor, tutor, and special education teacher. She is a graduate of Cornell University with a degree in policy analysis and management and has a master's degree in education from Brooklyn College. Kathryn is looking forward to bringing her passion for accessibility and educational justice into curriculum design at NGPF. During her free time, Kathryn loves embarking on cooking projects, walking around her Seattle neighborhood with her dog, or lounging in a hammock with a book.