# 2.9 Career skill: Writing expressions and equations

## Learning outcomes

Students will interpret and write verbal phrases and sentences as simple algebraic expressions and equations.

## Teacher preparation

### Time required for lesson

One class period. Homework time may be needed.

### Materials needed

- Chalkboard/whiteboard with chalk/pens
- Career cards (These will need to be cut apart before using them in class. Career cards can be printed on cardstock and laminated for future use.)
- “Writing Mathematical Expressions and Equations” worksheet
- Computer with projector and internet access to access the Occupational Outlook Handbook
- Optional: If you don’t have access to a computer and projector, you may print overviews of the careers discussed in this lesson and hand them out to students.

## Activities

- Write the words addition, subtraction, multiplication, and division on the board. Remind students that words and phrases often suggest math operations which can help us understand and solve problems. Have students come to the board and write natural language words that signify each operation. (For example, “is half as big as” signifies division.) (5-10 minutes)
- Write a word sentence such as “Jose is three years older than ten” to guide students to translate into mathematical symbols (J = 3 + 10). Ask students to explain why the letter J is used in this equation. Use the “Writing Mathematical Expressions and Equations” worksheet to find additional examples to use with the students. (5-10 minutes)
- Brainstorm different careers that may need to translate expressions/equations into mathematical terms in order to communicate with their fellow workers or the general public. Be sure that the following are included in the list: stockbrokers, technical writers, research assistants, newscasters, surveyors, architects, landscape artists, and pharmacists. As careers are mentioned, discuss them with the class, and ask how they might need to translate from mathematical terms into natural language or vice-versa. Information about these and other careers can be found in the Bureau of Labor Statistics’ Occupational Outlook Handbook. (15 minutes)
- Put students into groups of three or four and give each group a career card. Have each group create at least four mathematical expressions/equations that might be used by people in the group’s assigned career. You may need to brainstorm with students some of the responsibilities of these careers. You can also change the career cards to meet your own classroom needs. (20 minutes) Examples include:
- For the career card “stockbroker,” an expression that could be created by the students: “Dell’s stock value has risen 3.2 points in the last quarter.” This would be translated to “x + 3.2,” where x represents the current stock value of Dell.”
- For the career card “pharmacist,” an expression that could be created by the students: “The CVS pharmacist needs to decrease the dosage of the medicine by half.” This would be translated to “x/2” or “1/2x” where x represents the original dosage.

- Ask each group to come to the board to write, in words, its expressions. Ask the other students to try to translate the expressions into mathematical symbols. (10 minutes)
- Hand out the “Writing Mathematical Expressions and Equations” worksheet and have the students complete it. Students who don’t finish may complete the worksheet as a homework assignment.

## North Carolina curriculum alignment

### Mathematics (2004)

#### Grade 7

**Goal 1**: Number and Operations - The learner will understand and compute with rational numbers.**Objective 1.02**: Develop fluency in addition, subtraction, multiplication, and division of rational numbers.- Analyze computational strategies.
- Describe the effect of operations on size.
- Estimate the results of computations.
- Judge the reasonableness of solutions.

- Common Core State Standards
- Mathematics (2010)
#### Grade 7

- Expressions & Equations
- 7.EE.4Use variables to represent quantities in a real-world or mathematical problem, and construct simple equations and inequalities to solve problems by reasoning about the quantities. Solve word problems leading to equations of the form px + q = r and p(x...

- The Number System
- 7.NS.3Solve real-world and mathematical problems involving the four operations with rational numbers.1

- Expressions & Equations