• 03/20/14   |   Adjusted: 01/10/17   |   1 file

# Domino Effect

Author: Mathalicious

• Description
• Files

Mathematically:

• Addresses standards 8.F.A.3, 8.F.B.4, and 8.F.B.5
• Reinforces multiple representations of a function through the use of input/output tables, graphs, and equations
• Requires students to interpret unit rate as slope (rate of change)
• Deepens students’ understanding of slope, $y$-intercept, and domain by having them apply it in a real-world situation
• Allows students to explore plausibility of answers and connect the meaning of mathematical models to a situation in the introduction of the lesson

In the classroom:

• Captures student attention by using an engaging context
• Provides robust opportunities for students to discuss mathematical concepts; includes guiding questions for teachers to use to facilitate discussion
• Uses technology to create a graph and illustrate the mathematics of the lesson
• Offers multiple opportunities for student practice by analyzing pizzas of various sizes

• Making the Shifts

How does this lesson exemplify the instructional Shifts required by CCSSM?

 Focus Belongs to the major work of eighth grade Coherence Builds on unit rates from seventh grade (7.RP.A) and students' understanding of representing situations with equations (7.EE.B.4a); lays foundations for work students will do in high school building functions to represent more complex situations (F-BF.A) Rigor Conceptual Understanding: secondary in this lesson Procedural Skill and Fluency: not addressed in this lesson Application: primary in this lesson
In this lesson, students learn to calculate the price of a pizza by interpreting the unit rate (per topping cost) as slope and by considering the initial cost of a pizza based on its size ($y$-intercept). Scaffolded questions lead students to calculate slope and $y$-intercept before ultimately finding the corresponding linear equation. There are short answer and open-ended questions, with opportunities for students to justify their answers. The lesson continues by giving students practice creating equations to represent the cost of additional pizzas with an unknown number of toppings. Students then compare the graphs for all three pizza sizes, both qualitatively and quantitatively.