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Domino Effect (Updated!)

How much does Domino’s charge for pizza?

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Domino Effect (Updated!)

How much does Domino’s charge for pizza?

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Check it out! This lesson was just updated in September 2024, and we hope you love the new and improved version. If you've already prepped an earlier version, fear not, you can still find those here through Thursday December 5, 2024.

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Domino Effect - Student Handout.pdf
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Domino Effect - Teacher Guide.pdf
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2023-2024 Versions

In the fall of 2024, Citizen Math released updated versions of every lesson in our library, plus a few new ones! We know you may have already prepped an earlier version or planned a repeat of last year, so we're continuing to make these earlier versions available through Thursday December 5, 2024.

You can find the new lessons through the regular search, and we hope you love them as much as we do. You can read more about these updates in Our Community.

How much is Domino’s really charging for pizza? Domino’s Pizza offers a high-tech website for customizing and tracking your pizza. But it’s hard to know how much the pizza actually costs until right before you buy it.

In this lesson, students use slope, y-intercept, and linear equations to explore the costs of different-sized pizzas at Domino’s and debate whether the pizza chain should be more transparent in its pricing.

REAL WORLD TAKEAWAYS

  • Posted prices can affect consumer behavior. Businesses choose when and how to share the price of items.
  • Sometimes businesses don’t reveal the price of an item until the end of the ordering process.

MATH OBJECTIVES

  • Given two points, calculate the rate of change (slope) and the y-intercept, and interpret them in a real-world context
  • Write a linear equation from a rate of change and y-intercept
  • Graph and interpret a linear function
Great anytime, including at the beginning of a unit before students have any formal introduction to the topic.
Grade 8
Writing Linear Equations
Grade 8
Writing Linear Equations
Content Standards 8.F.4 Construct a function to model a linear relationship between two quantities. Determine the rate of change and initial value of the function from a description of a relationship or from two (x, y) values, including reading these from a table or from a graph. Interpret the rate of change and initial value of a linear function in terms of the situation it models, and in terms of its graph or a table of values. A.CED.2 Create equations in two or more variables to represent relationships between quantities; graph equations on coordinate axes with labels and scales. A.REI.12 Graph the solutions to a linear inequality in two variables as a half- plane (excluding the boundary in the case of a strict inequality), and graph the solution set to a system of linear inequalities in two variables as the intersection of the corresponding half-planes. F.IF.5 Relate the domain of a function to its graph and, where applicable, to the quantitative relationship it describes. For example, if the function h(n) gives the number of person-hours it takes to assemble n engines in a factory, then the positive integers would be an appropriate domain for the function. F.BF.4 Find inverse functions. (a) Solve an equation of the form f(x) = c for a simple function f that has an inverse and write an expression for the inverse. For example, f(x) =2 x<sup>3</sup> or f(x) = (x + 1)/(x &mdash; 1) for x = &dash;1. (b) (+) Verify by composition that one function is the inverse of another. (c) (+) Read values of an inverse function from a graph or a table, given that the function has an inverse. (d) (+) Produce an invertible function from a non-invertible function by restricting the domain.
Mathematical Practices MP.4 Model with mathematics. MP.5 Use appropriate tools strategically.

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