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SWBAT evaluate algebraic expressions by substituting integers in a game of trashketball.

Big Idea

Students practice evaluating algebraic expressions through a fun group game.

Do Now

10 minutes

Students enter silently according to the Daily Entrance Routine. The Do Now on their desk will assess their understanding of the vocabulary in preparation for tomorrow’s vocabulary quiz. The last three questions aim at assessing and later discussing some of the most commonly misunderstood topics of change and difference. The key points I address during this part of class are:

  • Difference does not mean subtract; it means the number of units between two values. This means difference will always be positive because it only measures distance.
  • Change indicates direction and therefore requires a sign to indicate it. Change can be either positive or negative because it measures magnitude AND direction.
  • For the last questions I will emphasize the use of visuals as a tool for solving.

Class Notes + Intro to Lesson

15 minutes

The following definitions are written on the black board. Students are asked to copy down these definitions on their notes sheet.

  • Evaluate: to find the value of an expression
  • Variable: a letter or other symbol used to represent an unspecified number or value

Students who finish copying early will be asked to solve the sample problems at the bottom of their notes on the board. As other students finish they will be asked to work with partners to complete the same examples. I give students 5 minutes to attempt the problems. Then I take 5 minutes to review the answers. By allowing students to work with partners, I am able to pull a smaller group aside and work with them on evaluating. I choose these students working with me by using MAP data gained the day they took the MAP test. I pull the 6 lowest students based on their "number sense" strand results. 

Some of the most rigorous evaluation questions include problems with exponents and problems with negatives. Having a small group allows me to use visual aids to help students access the concepts concretely. For example, in the example that states k=–4, and students are asked to evaluate -k. A common misconception is to assume that the negative sign in front of k is the same as the negative in front of the 4. By using a sticky note to demonstrate substitution up close, students are able to understand the evaluation the following wak:

–k = – (–4) = +4

Students transition to Trashketball by putting away their homework sheet and binders and have only a pencil in hand. 

Task - Trakshetball

25 minutes

Recycled paper is used to show work for this game. We start off by counting off by 4 so that students can create groups of 4 (or 3). These 5 - 6 groups split up in the room and work together to solve questions displayed on the power point. Each student is assigned a letter from T-R-A-S-H (Some students will need to double up on letters). Questions are displayed in the power point and are on a timer (already built into ppt). At the end of 2-3 minutes, a letter is displayed. The student assigned that letter must come up to the board to show me their work and answer. Students with correct answers will get their paper back and students without correct answers will not. The sheet of paper returned will be used as points at the basket.

The problems included in the game will allow students to practice integer operations with more than one integer, evaluating algebraic expressions and identifying number lines to match real world problems. These are rigorous problems for students at the beginning of 7th grade. Mixed groups are ideal for this task so that students can persevere in solving each problem with the help of their neighbors (MP1). I'm hoping that this will add motivation and will build up our team so that students feel comfortable tackling tough problems together. 


10 minutes

Students take shots with their earned correct-answer papers. There is a 3 point line and a closer two point line into the trash basket. Points are totaled per group. Groups earn achievement points to be shared among the groups with their shots.

Careful management expectations need to be set for this part of class. Students are asked to elect one student to shoot for points. This student collects all of the points for the table and tables are called up to the basket in clockwise order starting with the first table to SSLANT (Sit Up, Smile, Listen, Ask/Answer Questions, Nod, Track). Student NOT shooting for points are responsible for shouting out encouraging statement. All other students have to option to support their teammates positively or say nothing at all. Any team that is responsible for any negative behavior will have shots/points taken away.