Algebra: Adding and Subtracting Linear Expressions

thingiverse

This activity uses algebra tiles to build linear expressions with integer coefficients. How I Designed This: I designed this using TinkerCad to create rectangles with 'x' holes and squares with '1' holes. Standards: CCSS.Math.Content.7.EE.A.1 Apply properties of operations as strategies to add, subtract, factor, and expand linear expressions with rational coefficients. This lesson meets the following standard: CCSS.Math.Content.7.EE.A.1. Students will learn how to build and combine linear expressions with integer coefficients. Lesson Plan and Activity: Start by guiding students through an example. We want to combine (2x+3) + (x+1). Show them how to set up these two expressions [Figure 1]. Next, have students count or group together all of the x's to see that there are a total of three and do the same for the ones to see a total of four. They should write out the result as 3x + 4. Once they understand how this works, students can work on more examples on their own or in groups. Then, guide them through a subtraction example. To subtract (2x+3) - (x+1), take away from the first group the number of x's and 1's in the second. We are left with x + 2 [Figure 2]. See the files section for a handout. Figure 1: Figure 2: Skills Learned: algebra Duration of Lesson: one class period Preparation: Print these manipulatives out ahead of time. The amount you need to print will depend on how many students you have and if you want them to work in groups. If you want students to be able to combine a lot of x's and 1's together, you may want to print 30 of each per student/group.