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Pizza Pi (Updated!)

Which pizza size is the best deal?

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Pizza Pi (Updated!)

Which pizza size is the best deal?

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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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Pizza Pi - Student Handout.pdf
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Pizza Pi - 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.

Should you ever order a personal-sized pizza from Pizza Hut? Pizza Hut pizzas come in large, medium, and personal. While the smallest size is the least expensive, it costs the most per square inch and is over half crust!

In this lesson, students calculate circle areas to compare the unit costs of different sized pizzas, find the percent of pizza that is tasty inside vs. crust, and debate whether it’s ever a good idea to order a personal-sized pizza from Pizza Hut.

REAL WORLD TAKEAWAYS

  • Larger pizzas may cost more in total, but they typically cost less per square inch.
  • A pizza consists of two main components: the crust and the inside part (with the cheese and toppings).
  • For a given crust thickness, the smaller the diameter of the pizza, the greater the percent that’s made up of crust.
  • Personal-sized pizzas are over half crust.

MATH OBJECTIVES

  • Calculate the area of a circle
  • Use geometric models to solve real-world problems
  • Use unit rates or proportional reasoning to determine the best deal
Appropriate most times as students are developing conceptual understanding.
Grade 7
Measuring Circles
Grade 7
Measuring Circles
Content Standards 7.G.4 Know the formulas for the area and circumference of a circle and use them to solve problems; give an informal derivation of the relationship between the circumference and area of a circle.
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.7 Look for and make use of structure. MP.8 Look for and express regularity in repeated reasoning.

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Great anytime, including at the beginning of a unit before students have any formal introduction to the topic.

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