Algebra tiles are a great way to teach your students how to simplify expressions. If you are not familiar with Algebra Tiles, firsts read my previous post here.
To begin, Students need to understand what a zero pair is. A zero pair, is made by opposites that cancel out to be zero. For example, -2 and 2 are a zero pair. 2n and -2n are a zero pair.
Next, students need to understand that pieces that are the exact same size are called like terms. Like terms can be combined. Have students represent the expression 2n + 5 + n + 2.
Explain to students that we need to combine our like terms, the pieces that are the same size. Therefore, we can combine the 2n and the n to make 3n and we can combine the 5 and the 2 to make 7.
Have students try several problems like this, with only addition. When students have mastered that, have students represent 5n + 4 + n – 1.
Have students combine the like terms.
Then, have students cancel out any zero pairs. In this problem, the minus 1 and positive 1 make a zero pair. The remaining pieces are your answer. 5n + 2.
Have students try several problems similar to this until they are comfortable. You can also add in exponents. For instance, g² + 2g + 2 – g + g².
Students should first combine the like terms.
Then, cancel out any zero pairs. The final answers would be 2g² + g + 2.
Once you have spent a significant amount of time practicing simplifying expressions with the Algebra tiles, you can move to practicing simplifying expressions with paper and pencil. Make sure you always spend time with the hands-on lesson before moving to paper and pencil. The visual helps students understand what they are doing. Please comment below if you try this lesson in your classroom and let me know how it goes!