Ask students to describe a situation that revolves around a variable. For example, a student might tell a story about how John and Michelle can go to the movies only if it does not rain. The weather in this case is a simple variable. A more complicated project might require students to isolate two different variables in a situation. For example, John and Michelle can go to the movies if the family car is available, and the car is only available if their mother is home. While this project does not involve calculating the numerical value of a variable, it will help students develop a broader understanding of a variable.
In this project, a teacher tells students that they must come up with 15 to 20 equations with a sum of 30 and a variable value of, for instance, x=5. Students will then think of a series of equations, for example: 6x = 30, 10x - 20 = 30, that equal 30. This teaches students how to manipulate variables and requires a few hours of practice from each student who completes the project.
Students design a game like Jeopardy that revolves around calculating the value of different variables. Classmates compete in teams while playing each student's Jeopardy game. A student may design a question such as "4x + 3 = 15, What is X?" and his classmates compete to answer the question first. This project involves the student thinking hard about variables and her classmates practicing their algebra by trying to answer the questions.
In this more advanced project, students must juggle two different variables to help a baseball player hit a home run. The students are told to imagine two, three or four relevant variables. For example, how windy is the day, how fast the ball is thrown, how fast the bat is swung, how far away is the home run fence? They must pick a few variables and design an equation that determines how far the ball goes when it is hit and whether it goes over the fence. The student then explains the equation to his classmates and practices filling in certain variables and having his classmates calculate the others. This project involves the whole class and also has individual students think closely about variables are and how to use them.