# Ch 3: Solving Proportion Word Problems: CCSS.Math.Content.7.RP.A.3

Assign your 7th-grade students the videos in this chapter to supplement your classroom instruction about solving ratio and proportion problems in real-life scenarios. Also included are suggestions on ways to incorporate the lessons and assessments in your classroom.

Standard: Use proportional relationships to solve multistep ratio and percent problems. Examples: simple interest, tax, markups and markdowns, gratuities and commissions, fees, percent increase and decrease, percent error. (CCSS.Math.Content.7.RP.A.3)

Comprehension of the material in this chapter will increase students' competence in working with ratios as a percentage, particularly in the context of word problems. This will enhance their mathematics capacity and test-readiness in general, but this chapter has the added benefit of being incredibly relatable in day-to-day situations. This helps students become more competent in the arithmetic of daily life. The concepts covered in this chapter cover:

• Understanding proportional relationships in multistep ratio and percent problems
• Constructing proportions while solving real-world problems
• Solving interest, commissions, tip, price markup, and tax/discount problems
• Calculating percentage increase and decrease

Students will exhibit mastery of the lessons in this chapter when they are able to deconstruct common word problems involving various percentage-based ratios, reorder or change the notation of incongruent elements of the equation, and solve for the missing element(s). Their understanding of these topics will be readily evident in both the classroom and to their parents at home as they navigate the very problems presented here in real life.

### How to Use These Lessons in Your Classroom

Looking for an interactive way to incorporate these lessons into your classroom instruction? Here are some examples of how you might do so.

#### Who wants to be a used car salesperson?

Have students watch the How to Calculate Sales Commissions video. Pair students off with one acting as a car salesperson and the other as a prospective client. Give each student in the pair a type of car and its worth as rated on a common used car site. Provide the salesperson with a commission rate and minimum commission goal. Provide the client with a maximum budget (they are paying cash). Negotiations begin with the salesperson presenting a figure which benefits them greatly and they think the client may go for. The client then determines if the price is within their budget, declining the offer if it is not. Negotiations continue until the salesperson makes an offer which fits in the client's budget but still makes a profit for them and the company. Switch roles to give each student practice on both sides of the negotiation.

#### Calculating markups homework

Assign the How to Markup a Price video as homework. Have students watch the video and then develop a business plan for selling their own t-shirts. Have them research t-shirt vendors and screen printers to determine the costs of running such a business from their home (no overhead). After finding an appropriate vendor and determining the price of creating their shirts, they will decide how much they are going to sell the product for to make a target profit (e.g. \$10 per shirt).

#### Calculating savings

Take a coupon page out of the local newspaper or print information on a sales event from an online source. Have students work out the missing starting/ending prices, percentages, or total savings. For example, an ad offering a 30% discount on cardigans, now costing only \$70, has two missing elements: initial price and amount of savings (\$100 and \$30 respectively). Of course each ad must have at least two of the four elements for the math to work out: an ad indicating only a percentage off without prices would be impossible to work with. This can be assigned as homework, in-class work, or a quiz.

8 Lessons in Chapter 3: Solving Proportion Word Problems: CCSS.Math.Content.7.RP.A.3
Test your knowledge with a 30-question chapter practice test
Chapter Practice Exam
Test your knowledge of this chapter with a 30 question practice chapter exam.
Not Taken
Practice Final Exam
Test your knowledge of the entire course with a 50 question practice final exam.
Not Taken

### Earning College Credit

Did you know… We have over 160 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.