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# Domino Effect

## How much is Domino’s really charging for pizza?

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 – or the fact that they’re hidden! – affect consumer behavior. Businesses choose when and how to share the price of items.

### MATH OBJECTIVES

• Given two points, calculate the rate of change between them
• Write a linear equation from a rate of change and y-intercept
• Graph a linear equation

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