➕ 7th Grade Math · Unit 3

Ratios and Proportional Relationships

20 short narrated lessons in 4 chapters, each with pictures, a quiz with a hint and a second try, and an explanation for every answer.

Standards: 7.RP.A.1 7.RP.A.2 7.RP.A.3

Picture from the lesson “Rates and Unit Rates”
Rates and Unit Rates
Picture from the lesson “Complex Fractions”
Complex Fractions
Picture from the lesson “Unit Rates with Fractions”
Unit Rates with Fractions

What your child will learn

Unit rates with fractions

  1. Rates and Unit RatesFind a unit rate, like miles per hour, as the amount for one unit of the second quantity.
  2. Complex FractionsSimplify a complex fraction like one half divided by one fourth by dividing the fractions.
  3. Unit Rates with FractionsFind unit rates like walking one half mile in one fourth hour equals two miles per hour.
  4. Comparing Unit RatesCompare unit rates to decide which deal or speed is better.
  5. Unit Rates with Fractions Review ReviewReview finding unit rates, including rates with fractions, and comparing them.

Proportional relationships

  1. Testing Tables for ProportionalityDecide whether a table shows a proportional relationship by checking for equivalent ratios.
  2. Graphs of Proportional RelationshipsTell whether a graph shows a proportional relationship by checking for a straight line through the origin.
  3. The Constant of ProportionalityFind the constant of proportionality from a table, graph, equation or description.
  4. Writing Equations Like y equals k xWrite an equation like y equals k x for a proportional relationship and explain what the point one comma k means on its graph.
  5. Proportional Relationships Review ReviewReview recognizing proportional relationships in tables and graphs and writing y equals k x equations.

Percent problems

  1. Solving Percent Problems with ProportionsFind a part, whole or percent using a proportion or an equation.
  2. Percent Increase and DecreaseFind the percent a quantity went up or down compared with the original amount.
  3. Percent ErrorFind percent error by comparing an estimate or measurement with the actual value.
  4. Simple InterestFind simple interest by multiplying the principal, the rate and the time.
  5. Percent Problems Review ReviewReview percent proportions, percent change, percent error and simple interest.

Percents in everyday life

  1. Sales Tax and TipsFind the sales tax, tip and total cost of a purchase or meal.
  2. Markups and DiscountsFind sale prices after a discount and store prices after a markup.
  3. Commissions and FeesFind how much a salesperson earns from commission or how much a fee adds to a cost.
  4. Percents in Everyday Life Review ReviewReview sales tax, tips, markups, discounts, commissions and fees.
  5. Unit 3 Test: Ratios and Proportional RelationshipsShow what you learned in the whole unit (Unit rates with fractions, Proportional relationships, Percent problems, Percents in everyday life) by answering mixed questions.

Try a question from this unit

From the lesson “Rates and Unit Rates”

A garden hose fills a 150-gallon water trough in 6 minutes. What is the unit rate in gallons per minute?

  • 25 gallons per minute
  • 900 gallons per minute
  • 1/25 gallon per minute
  • 144 gallons per minute
Show the answer

25 gallons per minute. Gallons per minute means gallons divided by minutes: 150 ÷ 6 = 25 gallons each minute. The choice 1/25 comes from dividing in the reverse order, and 900 comes from multiplying instead of dividing.

Hint kids see after a wrong try: “Per minute means the amount for one minute. Decide which quantity belongs on the bottom before you divide.”

Key words

  • rate
  • unit rate
  • complex fraction
  • better buy
  • proportional
  • equivalent ratios
  • origin
  • straight line
  • constant of proportionality
  • equation
  • percent
  • proportion
  • percent increase
  • percent decrease
  • percent error
  • simple interest
  • principal
  • interest rate
  • sales tax
  • markup
  • discount
  • markdown
  • commission
  • fee

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