Every year, I introduce the concept of solving two-step equations using “penny puzzles,” and every year, it leaves a lasting impression on my students. They enjoy the challenge of the puzzles and the process of taking an active role in their learning. Once my students get the hang of solving these puzzles, there is an vibrant energy to the classroom. My students are engaged and excited, and when they are directed to follow up the activity with the accompanying worksheet, they have no problem creating and solving two-step equations.
Prior to the activity, I prepare five or six trays modeling the penny puzzles pictured in the “Penny Puzzle” comic. Each tray is numbered and contains sealed paper lunch bags with the same amount of pennies in each, a certain number of loose pennies and a card with the total amount of pennies written on it. For the activity, students will break into teams based on the number of trays prepared. I usually prepare five or six trays. I begin the lesson by projecting and handing out the comic. We read it as a class and discuss the strategies used to solve the puzzles. As modeled in the comic, each team will have to examine the contents of the tray to determine how many pennies are hidden in each bag without peaking. I require my students to write out the equation being modeled prior to solving the puzzle. Once they solve the puzzle in their given tray, the students put all of the contents back the way they found it and pass it to another team.
The next part of the activity requires the teams to make their own penny puzzles. This proved to be a bit of a challenge for some of my teams, and they needed some guidance. Many of my students referenced the comic to examine how the characters created puzzles, and in the end, every team was able to successfully create a penny puzzle to test on classmates. As they did in the first portion of this lesson, the students passed the trays around and attempted to solve their classmates’ puzzles.
Through the entire activity, the classroom was abuzz with energy and excitement. My students love this activity, and it has always proved to create a solid foundation for my students’ understanding of two-step equations. Once I move on to actually solving written equations, I reference which terms represent the penny bags and which terms represent the loose coins. This helps my students identify which terms get added or subtracted and which get divided. This is a very effective introductory activity, and I recommend it to anyone introducing algebra. The download on this site provides the comic, teacher instructions and a follow-up practice worksheet.
Download this lesson plan on this website or on Teachers Pay Teachers