Need some strategies for teaching independent and dependent variables in math? This article gives a few tried-and-true activities, and offers some fun suggestions that can be tailored to fit your students’ needs.
Independent and Dependent Variables Across the Disciplines
Math class is not the only place students will encounter variables. Variables are also found in most science classes, and even some language arts and social studies classes.
In the latter two, however, variables are often thought of in a very different way. Science classes approach variables in much the same way as math classes, and even use the terms independent and dependent. It might be helpful for you to make this connection for students in order to point out that this is not just a math topic! You can also draw from the other disciplines as you come up with examples to use in each of the activities below.
Although I’ve never heard of an agreed-upon name for this type of activity, I’ve always just called it ‘Snake.
‘ In pairs (or individually in advanced classes), have students come up with a unique example of a situation that contains independent and dependent variables. You can offer the following as a suggestion: Eva’s grandfather agrees to pay her $15 for every hour that she helps run his small shop. One day, she works for 2 hours after school. How much will Eva be paid that day? In this example, the number of hours worked is the independent variable and the amount Eva will be paid is the dependent variable.
Once students create their unique example, set a pattern around the room that the examples will move through. This usually can efficiently be done by snaking around the room from row to row. Thus, the name ‘Snake!’ Give students (or pairs) a few minutes with each example and ask them to keep a running list of their answers on a sheet of paper before they pass the examples on. The nice thing about this activity is that students will have their answers in the same order (although they won’t all start with the same one), so it is easy to go over the answers as a class.
There are so many different activities you can do with a classroom set of individual whiteboards. Tip: If you go to your local home improvement store, they will usually be happy to give you a teacher discount, and will more than likely cut a large whiteboard into smaller boards for you.
A great way to really hammer home the idea of independent and dependent variables is to write (or find) a large number of examples, then read them to the class. When you’re finished reading one, call out one of the variables and ask students if it is the independent or dependent one. Simply have them write I or D on their whiteboards.
Having your students hold them up for you to see is a great way to get some formative data on how they are doing with the concept. Another activity that is simple and fun is to have students draw a line through their board to divide it in half. The top half can be the area in which they will write the independent variable and the bottom half can be for the dependent variable. For each example you read, have them write down both variables. This will be a bit more challenging, but can definitely help students solidify their understanding of the difference between the variable types.
Having students distinguish between independent and dependent variables lends well to a variety of classroom games. You could have students divide into teams (2 or 3 usually works best) and answer questions one at a time for a chance to shoot a ball into a basket for points, or perhaps they simply earn points toward becoming the overall winner. Throw in a few prizes, and this will be a spirited way to reinforce the concept.
Extension: Connect it Back to Science
A fun extension to this lesson might be to apply these new terms to an example from science. I tend to use a plant fertilizer example: a scientist wants to test which fertilizer works best to grow corn.
She applies three different fertilizers to three different corn plants and measures their heights. Which variable is the independent variable, and which is the dependent?In this scenario, the fertilizer is the independent variable (the input) and the height of the corn plants in the dependent variable (the output).Connecting this lesson back to science may just help some students see the usefulness of the terms independent and dependent variable.