##
* *Reflection: Developing a Conceptual Understanding
Multiple Percents - What happens when you have a discount and tax? - Section 2: Explore

As I was sort of anticipating, many groups thought the sweater would be free! I did not originally have this question in my lesson, I added it after block 1 (my advanced group) because they needed proof that you could not just add percents. The 50/50 discount is a great example because it hits home with kids that stores do not just give stuff away, so you must not be able to add the percents. I have included some video clips of groups discussing the question and trying to come up with an answer. I only had 5 tables the whole day get the question right before I taught the lesson!

*Developing a Conceptual Understanding: Discussion Question Reflection*

# Multiple Percents - What happens when you have a discount and tax?

Lesson 8 of 21

## Objective: Students will be able to solve problems involving multiple percentages.

## Big Idea: No no no!!! You CANNOT combine percents! In this lesson students will learn to avoid making one of the most popular percent mistakes.

*60 minutes*

#### Launch

*10 min*

**Opener: **As students enter the room, they will immediately pick up and begin working on the opener – Instructional Strategy - Process for openers. This method of working and going over the opener lends itself to allow students to construct viable arguments and critique the reasoning of others, which is **mathematical practice 3**.

**Learning Target: **After completion of the opener, I will address the day’s learning targets to the students. For today’s lesson, the intended target is, “I can solve multi-step percent problems.” Students will jot the learning target down in their agendas (our version of a student planner, there is a place to write the learning target for every day).

**Thoughts from Me! **Students will need to pay careful attention to precision when moving the decimal point and completing the calculations (**mathematical practice 6**). Percents lend themselves to real world application problems, requiring students to model and reason given models (**mathematical practices 2 and 4**). Students will be permitted to use tools as needed - calculators and bar models (**mathematical practice 5**).

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#### Explore

*45 min*

**Discussion Question: **To start the lesson off, I am going to pose the following question to my students: "A sweater is priced $60. It is on sale for 50% off. Later it goes on sale for an additional 50% off. What is the price of the sweater?" The point of this discussion question is to introduce kids to the fact that they cannot combine percents, they must calculate them seperately. Many students I am sure will think that the sweater is free - but this opens up good discussion and gets kids interested in the lesson.

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#### Summary

*5 min*

**Exit Problem: **To summarize this lesson, I will have students complete an exit problem on the back of their opener. We have been working on the same concept for 8 lessons, so at this point I am looking for some individual feedback on understanding. This exit problem will give me insight into who understands tax, discount, and a combination of both concepts.

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When I first saw the grid on the word document, I thought the students would be playing a "Tic-Tac-Toe" or "Connect Four" type game. Get an answer right and you can make an X (or O) in the space of your choosing. I see now this will not work with 14 questions. I might change it to 9 or 16 questions to add some competitiveness. I'll let you know how it works!! Thanks for the ideas! :)

| one year ago | Reply

- UNIT 1: Introduction to Mathematical Practices
- UNIT 2: Proportional Reasoning
- UNIT 3: Percents
- UNIT 4: Operations with Rational Numbers
- UNIT 5: Expressions
- UNIT 6: Equations
- UNIT 7: Geometric Figures
- UNIT 8: Geometric Measurement
- UNIT 9: Probability
- UNIT 10: Statistics
- UNIT 11: Culminating Unit: End of Grade Review

- LESSON 1: Percent Models - A Visual Approach to Percents
- LESSON 2: Markdown Percent Models - What Percent Are You Paying?
- LESSON 3: Markup Percent Models - Percents Over 100?
- LESSON 4: Percent Models Review - Practice, Practice!!
- LESSON 5: Percent Models Test
- LESSON 6: Finding Percents
- LESSON 7: Finding Percents Fluency - It's a Chain Reaction!
- LESSON 8: Multiple Percents - What happens when you have a discount and tax?
- LESSON 9: Markup and Markdown Review - Are you paying more or less?
- LESSON 10: Markup, Markdown, or Just a Percent? TEST
- LESSON 11: Working Backwards with Percents - What happens when a problem is not straightforward?
- LESSON 12: Working Backward with Percent: Practice Makes Perfect!
- LESSON 13: Performing with Percents - Can you bust some common misconceptions?
- LESSON 14: More Practice with Percents - Practice Makes Perfect!
- LESSON 15: Working Backward and Forward...TEST!
- LESSON 16: Percent Change - By What Percent Did the Value Change?
- LESSON 17: Percent Change - More Practice
- LESSON 18: Simple Interest - Understand Your Money!
- LESSON 19: All Percents Review
- LESSON 20: All Percents Test
- LESSON 21: Proportional Reasoning and Percent - Can you apply the concepts? (3 Day Lesson)