## Reflection: Real World Applications Writing Piecewise Functions - Section 2: Writing Piecewise Defined Functions

When working with real world problems it is important to realize students will struggle with many ideas.  The electricity problem is difficult for most adults to understand.  I guide students thinking by using different values for the kilowatts.  I ask "how much will the charge be if only 500kwh are used? 550? 601? etc." This really helps students understand what is going on.

At first glance students think that the customer is getting charged more for 400 and then charged for 600. Seeing how the 600, 400 and 1173 relate to the total usage is important in understanding this problem.

I like this problem due to the relevance and how most people do not realize how the electricity company actually determines the bill.

Students Struggling
Real World Applications: Students Struggling

# Writing Piecewise Functions

Unit 2: Functions and Piecewise Functions
Lesson 3 of 15

## Big Idea: Write a function to find the energy cost for customers.

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Standards:
Subject(s):
Math, Precalculus and Calculus, piecewise-defined functions, modeling, function
40 minutes

### Katharine Sparks

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