## Loading...

# Linear Expressions and Word Problems

Lesson 4 of 20

## Objective: SWBAT write and match linear expressions to word problems

## Big Idea: Students analyze and match algebraic expressions to word problems. Students then write some algebraic expressions to represent word problems.

*55 minutes*

#### Introduction

*15 min*

I will begin with a question: "What does the term algebraic expression bring to mind?" I will have a simple word web organizer drawn on the SmartBoard. As students contribute answers, I will draw in the connections on the word web. Hopefully students come up with answers like: they involve variables, numbers, operations, represent word problems, etc...

This is not only to assess prior knowledge but to also have students show see how much they already know about expressions. I will try (emphasis on "try") to make every relevant response a correct answer so that students feel free to contribute their thoughts. Almost every time I do this, I am pleased with how much useful information students are able to contribute.

Then I will present four simple statements in the resource. We will work together to match the statement to the expression. For each expression, we will discuss what the variable means in context to the verbal statement.

Note that a couple of the statements may have more than one matching expression depending on the perspective you take in the problem.

All of this is a simple exercise to prepare students for the work ahead in the next section. This is also an exercise in **MP1 ** - specifically connecting the relationship between verbal descriptions and expressions.

#### Resources

*expand content*

#### Gallery Walk and Discussion

*20 min*

Logistics:

Before the lesson:

I'll place the 6 verbal statements throughout the room.

I'll divide the class into 6 groups based. (These may be mixed ability groups)

I'll need enough sticky notes for each student to have 6.

During the lesson:

I'll have students copy the 6 algebraic expressions onto their sticky notes - one expression per sticky note.

I'll explain that they will rotate with their groups to the statements around the room. They are to pick the expression that they think best matches the statement. They should place their sticky note on that expression.

I will set the timer for about 1-2 minutes before rotating. Of course, I'll judge whether or not it appears they need more or less time and adjust accordingly.

Once all of the statements have been placed we will discuss the responses.

I purposely did not include a question with the statements, so that for each I can ask: What question could the expression answer? For each expression we will discuss what each part (coefficient, constant, variable, operations, etc) represents.

I expect for there to be some disagreement over several of these since they all use 10, 15 and x. Students will often confuse 10x + 15 with 15x + 10 or even 10x + 15x. This activity should bring about all of the misconceptions.

*expand content*

#### Writing Expressions

*15 min*

Now students will have a chance to write algebraic expression to represent some word problems. I'll have students work for the first several minutes by themselves before they will be allowed to check in with a neighbor. The first 4 problems are 1-step expressions. The last two are 2-step expressions which is right where the common core expects 7th grade students to be. We will briefly discuss answers before beginning the exit ticket.

#### Resources

*expand content*

#### Exit Ticket

*5 min*

There are 4 question on the exit ticket. Two are multiple choice to represent the matching algebraic expressions to statements part of the objective. The other two are open ended to match the writing algebraic expressions to statements part of the objective. The first two problems are one-step expressions and the last two are two-step expressions.

A successful exit ticket will be measured as at least 3 correct responses out of 4.

#### Resources

*expand content*

##### Similar Lessons

Environment: Suburban

Environment: Urban

Environment: Urban

- LESSON 1: Simplifying Linear Expressions by Combining Like Terms
- LESSON 2: Expand Algebraic Expressions Using the Distributive Property
- LESSON 3: Factor Algebraic Expressions Using the Distributive Property
- LESSON 4: Linear Expressions and Word Problems
- LESSON 5: Solving Addition and Subtraction Equations Using Models
- LESSON 6: Solve Addition and Subtraction Equations using Inverse Operations
- LESSON 7: Solve One-Step Equations Using Inverse Operations
- LESSON 8: Diagrams of Two-Step Equations
- LESSON 9: Speeding Tickets
- LESSON 10: Translate Verbal Statements to Inequalities
- LESSON 11: Graph Inequalities on a Number Line
- LESSON 12: Solve Inequalities Using Addition and Subtraction
- LESSON 13: Solve Inequalities Using Multiplication and Division
- LESSON 14: Solve Two-Step Equations Using Inverse Operations
- LESSON 15: Equation and Inequality Reteach - Fraction Coefficients
- LESSON 16: Algebraic Expressions and Equations for Shape Patterns
- LESSON 17: Simplify Expressions Containing Fractions by Combining Like Terms
- LESSON 18: Simplify Rational Number Expressions Using the Distributive Property
- LESSON 19: Writing Algebraic Expressions to Solve Perimeter Problems
- LESSON 20: An Introduction To Programming in SCRATCH