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To Have and to Hold

Is it a good idea to rent a storage unit?

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To Have and to Hold

Is it a good idea to rent a storage unit?

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Is it a good idea to rent a storage unit? Americans love their stuff. There are more storage facilities in the United States than there are McDonald’s and Starbucks combined. But are people spending more on storage than their stuff is worth?

In this lesson, students write and solve multi-step equations to evaluate whether storage unit rentals are worth the cost and make recommendations for when people should store, sell, donate, or toss their unused stuff.

REAL WORLD TAKEAWAYS

  • The cost of storage can exceed the cost of the items stored; whether or not a storage locker makes (strictly financial) sense depends on the value of the items in it and how long they’ll be stored.

MATH OBJECTIVES

  • Write and solve inequalities (or equations) in the form of px + q = r

Appropriate most times as students are developing conceptual understanding.
Grade 7
Equations & Expressions
Grade 7
Equations & Expressions
Content Standards 7.EE.3 Solve multi-step real-life and mathematical problems posed with positive and negative rational numbers in any form (whole numbers, fractions, and decimals), using tools strategically. Apply properties of operations to calculate with numbers in any form; convert between forms as appropriate; and assess the reasonableness of answers using mental computation and estimation strategies. For example: If a woman making $25 an hour gets a 10% raise, she will make an additional 1/10 of her salary an hour, or $2.50, for a new salary of $27.50. If you want to place a towel bar 9 3/4 inches long in the center of a door that is 27 1/2 inches wide, you will need to place the bar about 9 inches from each edge; this estimate can be used as a check on the exact computation. 7.EE.4 Use 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. (a) Solve word problems leading to equations of the form px + q = r and p(x + q) = r, where p, q, and r are specific rational numbers. Solve equations of these forms fluently. Compare an algebraic solution to an arithmetic solution, identifying the sequence of the operations used in each approach. For example, the perimeter of a rectangle is 54 cm. Its length is 6 cm. What is its width? (b) Solve word problems leading to inequalities of the form px + q > r or px + q < r, where p, q, and r are specific rational numbers. Graph the solution set of the inequality and interpret it in the context of the problem. For example: As a salesperson, you are paid $50 per week plus $3 per sale. This week you want your pay to be at least $100. Write an inequality for the number of sales you need to make, and describe the solutions.
Mathematical Practices MP.1 Make sense of problems and persevere in solving them. MP.2 Reason abstractly and quantitatively. MP.3 Construct viable arguments and critique the reasoning of others. MP.4 Model with mathematics. MP.8 Look for and express regularity in repeated reasoning.

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