Solving equations is foundational for middle and high school math. Students actually have been doing this since first grade! However, students can make careless errors or struggle when it comes to following the many procedural steps required to solve an equation.
In 6th grade CCSS, students are asked to solve one-step equations with positive whole numbers (6.EE.7). Seventh graders are asked to solve two-step equations (including distributing) with rational numbers (7.EE.7). And, lastly, 8th graders must be able to solve for multiple variables using their knowledge of systems of equations (8.EE.C).
Why the struggle?
Solving equations is very revealing. If your students struggle with integer operations, then it will show up again when solving equations. If your students struggle with rational number operations, then it will show up again when solving equations.
We asked our Facebook group what students mostly struggle with, and here are some of the responses:
- Combining like terms incorrectly
- Dividing/multiplying a negative coefficient. Students trying to add instead.
- Not distributing when they should. Example: 5 – 2(x + 2) = 10 simplifying to 3(x +2) = 10
- Students completing inverse operations on the same side of the equal sign instead of combining like terms
Does this sound familiar?
Use Algebra Tiles (No, really, use them!)
I was resistant! Manipulatives can cause undue stress (tiny items + 30 children); it is a lot! However, I think that if I had used algebra tiles in my classroom, students would have been way more engaged! I occasionally drew a model to demonstrate solving equations, but then Noelle showed me all the ways algebra tiles could be used to combine like terms, distribute, and solve two-step equations (even quadratics). I was on board!
Before using algebra tiles to introduce students to solving equations, use algebra tiles to demonstrate combining like terms. Combining like terms can be challenging for students, but when you ask students to combine all of the long green tiles (x), the long red tiles (-x), the small yellow tiles (+1), and the small red tiles (-1), it provides excellent concrete practice. It will also assist with zero pair understanding, which will be essential to solving equations with algebra tiles.
What would you rather combine as a student? The terms or the algebra tiles?
Let’s move on to solving equations. Look at the following example:
Before exposing your students to two-step equations with variables on both sides, let them practice with one-step equations first. Scaffolding is key. I chose this example to show you how versatile algebra tiles are (variables on both sides and negative values)
To isolate the variable, students would need to recognize that they needed to get rid of positive 2. To do this, they would add two negative tiles to make a zero pair. Adding negative 2 to one side would mean they would add to the other side to keep the equation balanced.
After students have removed the two zero pairs on the left side of the equation, they might be a little stuck. They are exploring, after all. Remind students that we want all variables on one side, since we want to find out what one x is equal to. Students would then add a negative x to both sides to create another zero pair.
Lastly, to get the solution for one x, students would divide the remaining red tiles among the two x tiles: X = -4.
Students are actually solving for x by undoing the problem, by using inverse operations (adding -2 to both sides and dividing by 2), and by keeping the equation balanced (they are adding tiles to both sides). All the procedural steps that might mean nothing to students in a traditional problem have meaning when students have been exposed to practicing with algebra tiles.
Remember that algebra tiles (like most manipulatives) exist to make the math visual. They provide conceptual understanding. Eventually, students will move into the algorithm. When students are exploring, make sure all of the solutions are integers (you can’t break the tiles into pieces).
If you don’t have access to algebra tiles, students can use this website.
These teacher tips from our Math Teacher VIP Facebook Group might help your students.
- Draw a line to separate the two sides of the equation.
- Do Undo Line – this is another strategy that can help students.
- Color-coding to help with combining like terms
- Making sure to actually say (and make students say), “2 times x equals 5” as opposed to “2x = 5.”
What additional tips do you have? Do you use algebra tiles in your classroom?