Algebra: Additional Strategies for Simplifying Expressions

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Objective

Aim 1: SWBAT subtract algebraic expressions and combine like terms to simplify. Aim 2: SWBAT simplify algebraic expressions and use substitution to verify their answers.

Big Idea

Students work over two days to achieve mastery on simplifying equations and using the distributive property

Do Now

10 minutes

For the next two days we will be reviewing a skill many students are struggling to master: simplifying algebraic expressions. Each day, students will enter silently according to the Daily Entrance Routine. Sprints will already be on their desks, faced down, with a heading printed across the top of each paper. Students must first write their names on the blank side, without turning their paper over. They will have 3 minutes to complete as many problems as possible. Time may be extended if I notice most students struggling to complete the entire sheet in three minutes.

After the given time, all students must stop and hand their paper to a neighbor. Pens should be taken out to check. I will point to each student to count off, snaking around the room and assigning a problem from the sprint to each student. Some may double on the first day of this review. I will correct any mistakes or fill any blanks if a student does not feel comfortable answering. After checking all papers, any student who answered more than 80% of the questions correctly will earn Achievement Points.

Our first sprint is one of many free resources found on the engageny.org website.  The second sprint is available online as a sample from the kutasoftware company. 

Class Notes: Review

10 minutes

After reviewing data and feedback from students on our algebra review lessons, I determine that we need more practice specifically with subtraction and simplifying algebraic expressions. This is an area most students need to improve and is connected to their mastery of the distributive property. On the first day of this review, I decide to share two strategies, shown in the video below: 

 

 

On the second day of our algebraic expressions review I wanted to show students a strategy for checking final answers. Using one example, I show students how to use substitution to check the answer. By substituting the same number for a variable into the initial expression as well as the simplified expression, students should notice that if the end values are equal, then their simplified expression is correct.

As always, students are encouraged to ask for help as I walk around with a whiteboard to show the strategies. All of these strategies focus student application MP6 – attention to precision. I notice many students making the common mistake of dropping negative signs and/or not taking care of checking work when combining positive and negative like terms.  For many of my students, a review of what it “like” vs “unlike” as well as a review of “zero pairs” is needed to simplify these expressions correctly.

Class Work

20 minutes

Students work in pairs for the first ten minutes of this section. As I walk around the room, I am targeting students that need to be pulled into small group remediation for the last 10 minutes of this section. These last 10 minutes must be spent completing the classwork silently. Ideally, I like to have no more than 5 students per group in these smaller settings, and no more than two groups working together in those last 10 minutes. It is important to push as many students as possible to work independently as the state exam gets closer. I need to see how much students can do on their own so that I may continue targeting smaller groups during remediation and study halls.

One of the smaller groups will be led by me and another by a student leader whom I feel confident can explain the topics without giving away the answers.

The classwork sheets for both of these days are pulled from the engageny.org website and student answers and work are to be completed on a separate sheet.

Closing

10 minutes

After the class work section has ended students will receive exit tickets. On the first day, students will work on their Exit Ticket until the end of class, making sure to include any questions still lingering about simplifying expressions. These questions along with the most common mistakes and strategies used will be shared out the next day before students work on the next Exit Ticket. Notice that classwork is extensive for both days, so it is included as homework as well.