Sunday, May 15, 2011

Writing Real Life Algebra Equations

After viewing the creation of an equation describing a real life situation, students create and illustrate their own algebra equation.

Learning Objective(s)
  • Translate real life situations into word problems.
  • Translate word problems into algebraic expressions and equations.
Assessment Type
This introductory lesson uses the presentation from NROC's Algebra 1--An Open Course, Unit 2 Topic 1: Solving Equations. It includes a low stakes formative assessment in which high school students create and illustrate a problem of their choice.
Assignment Details
  1. Let your class warm to the topic of making real life algebra equations. You can ask them to give examples of when they use math in real life or give them an example of your own. Have they ever had to write their problems down to figure them out? Tell them their objective for the day is to create a real life algebra problem of their own.
  2. View Unit 2, Topic 1: Solving Equations (4min). In this presentation, an equation is made to solve for the number of batches of cookies a person can make if they only have so much flour. In the presentation, "equation" is defined and properties of equality are also discussed. If you wish, you can have your students take notes.
  3. Lead the class through making a few example cookie batch equations—have fun with letting them choose ingredients and see how much they can do on their own (Socratic questioning techniques can help with this). Be sure to use correct algebra terminology as you go.
  4. When comfortable, break students into small groups (I suggest heterogeneous grouping) encourage them to discuss their favorite cookies amongst themselves to create a fun, excited atmosphere and lower apprehension about errors.
  5. Have students take about 30 min total to make and illustrate an equation for a cooking situation of their own. They should choose what they are going to make and what variable to solve for. (How many batches, X, can they make if they have 12 cups sugar to use up and the recipe calls for 4 cups of sugar in each choco-caramel cookie batch?)
  6. Have each group show you and each other what they've come up with after about 5-10min. This allows you to check their progress and give feedback as needed.
  7. Circulate the room checking on whether students have successfully made a real life equation. Once you approve a group's equation, give them a large piece of paper and marker to make their idea and equation into a large poster for your classroom.
  8. Students do not need to present a solution on their poster, unless they are done early and you need them to keep working on something! I prefer for the students to make the equation illustration with a large blank solution space. Then, the student-generated problems can be used as class warm ups in the future or student groups can trade and solve later.
Instructor Notes
  • Fun and innovation should be encouraged. If students would rather make up an equation about car parts and cars, have them go for it!
  • For a student who is feeling really stumped, the Unit 2 Tutor Sim, "Building a Swimming Pool,” can help with moving into representing word problems with symbols.
  • For students needing a challenge: Can they make up a real life problem that involves more than one step, a problem involving addition and multiplication for example?
  • For older students, a more grown up topic, could be used to make equations. Budgeting for a shopping trip or a vacation for example.
  • This is a very scalable activity. If you don't have much class time, individuals can just set up their equation problems in class, then illustrate at home.

As this is a formative assessment, emphasis should be on participation and an honest attempt at completing the task assigned.

If in a rush, you can use a basic, "Plus, check, minus," scale to represent 100%, 85%, 75%. Odds are low a group will earn less than that.

Alternately, if using a 10 point scale:

5pts -- Time on task. Students stayed engaged and on topic working to create their problem and present it. All students in the group supported one another and invited contributions from each other.
3pts -- Students created a neat and clear equation representing their problem and incorporating feedback you gave them. A word problem is written out, variables are defined, and the equation is shown.
2pts -- The equation is completely correct.

Total= 10pts

Hippocampus Correlation

Algebra 1--An Open Course, Unit 2 Topic 1: Solving Equations


Msteachetolearn said...


I love your blog! I am interested in doing the cookie recipe idea but I cannot find the lesson you are referring to.


Shaughn Lybrand

Laura Bost said...

Hi Shaughn,

So sorry for the confusion! NROC's working to release a new Algebra site that will contain the mentioned lesson, but the blog post ended up predating the actual release of the recording. It should be up by fall, and when it is a link will be provided.

For now, you could make up your own example and work it on the board. Better yet, bring in a pack of chocolate chips and make a problem using the recipe on the back and pretending you only have so many eggs (five, maybe), but plenty of everything else.

All the best, Laura