Graphing with Desmos
By Traci Zuniga (12th grade Math Teacher) and Sam Santiago (12th grade student)
This week in Ms. Zuniga’s College Algebra class at Roberto Clemente Community Academy, students are learning exponential functions on Desmos.com. Desmos is an interactive website that helps students with graphing and plotting points, building functions, and creating tables. Students started out working on an activity builder in which they matched a function to a graph. The activity was called “Match my line!” and was created by Ms. Zuniga to have students get a feel for the website. Students worked in a game mode to match the points on the line and see other students’ responses. Students also worked with partners to build a function for a table and a graph. Desmos is a great replacement for a graphing calculator. It is an awesome way to begin understanding and working with real world math problems!
Students also explored exponential models by calculating credit cards payments. Students were given a scenario of buying an iPod on a credit card with two different interest rates. Students were then tasked to find the balance of a $300 purchase after 6 years if no payments were made. The scenario had two different customers: Customer A had an annual rate of 18% and Customer B had an annual Rate is 36%. The students were given the opportunity to compare interest rates if they were charged both monthly and yearly by creating exponential growth models. Students used these exponential growth models to determine the advantages and disadvantages of a credit card and also to see how much profit the credit card companies are actually making off of purchases. Students will bring this task to life by applying their calculations in Desmos. Through Desmos, students can see other students’ graphs as they are working and communicate with each other to get help from their fellow classmates. Students will work together as a team to get more ideas from everyone else to get through the task.