# Selling Cake Pops Day 1 of 5

5 teachers like this lesson
Print Lesson

## Objective

Students will be able to write and solve equations from a business model.

#### Big Idea

Extend writing expressions into solving equations through modeling a student run business. Linear modeling as entry point to build students' algebra confidence.

## Warm Up

10 minutes

I include Warm ups with a Rubric as part of my daily routine. My goal is to allow students to work on Math Practice 3 each day. Grouping students into homogeneous pairs provides an opportunity for appropriately differentiated math conversations. The Video Narrative explains today's Warm Up- Selling Cake Pops Day 1 which engages students as they make sense and look for a possible context (Math Practice 1) for the warm up question, "would you rather make \$300 a week or \$7.50 an hour?"

I also use this time to correct and record the previous day's Homework

## Writing a Cost Expressions to Model Selling Cake Pops

38 minutes

Introduction

At one of the local farmers markets (that my mother vends at) there are some middle school girls who run a cake pop booth.  Those young ladies are the inspiration for this lesson and all of the information is authentic (locally).

As a hook, I'll ask students how many of them have been to one of the farmers markets in the area and continue with a discussion about how amazing local markets are for fresh produce, food and hand crafts.  Many of my students come from farming families so this will be quite meaningful and relevant. I’ll then guide the conversation to how it is the perfect place for anyone to explore being an entrepreneur and share the example of the young ladies selling cake pops.  They starting in the fall of ’12 and sold the entire summer of ’13.  We will be looking at their business and examining cost and potential profit from a business like this.

NOTE: I am introducing modeling using linear situations as a lead up to HSA-APR.A.1 which will include higher order polynomials. Concepts in this 4 day lesson are necessary scaffolding for my students transitioning to the Common Core Algebra 2 standards.

Ingredient Costs

The lesson today focused on the fixed and variable costs for the cake pop business.  First, we will look at the ingredient costs.  I give each pair of students a recipe for cake pops along with ingredient prices from our local grocery store.  Each pair will also receive a small stack of note cards so that you (the teacher) can collect the work and share out with the whole class. The directions are to figure out the “batch” costs for each ingredient and to then write an expression representing the cost of the cake pops.  For some students scaffolding is going to be VERY important at this point and this can be done as I walk around the room.  For example, students may need support finding the cost of the ingredients per batch.  An example of a guiding question would be: If eggs cost 1.89 per dozen but you only need 3, how could you find the cost for the three?  If I notice many groups struggling with the same elements, I would stop the class for a minute and ask for a volunteer to explain their process and reasoning.

A main goal of this lesson is to give students an opportunity to critique each other's work and reasoning (Math Practice 3).   I will write the different variations, both correct and incorrect, of the expressions that I collected from the note cards on the white board.  The class will then analyze the expressions, eliminated the incorrect ones, and discuss the pros and cons of the remaining expressions.  Precision (Math Practice 6) will most likely come up as students round differently in their calculations. This will generate good conversation among the students and you might find it helpful to review this "Rethinking Whole Class Discussion" Edutopia article.

The next task I will give my students is to find the expression representing the cost per cake pop.  I will follow the same procedure with the note cards.  It will be importance here to compare the equivalence of expanded and simplified versions of the expression.  This will be a common theme throughout this course.  The PowerPoint has scaffolding tips as the notes.

## Exit Ticket

3 minutes

I use an exit ticket each day as a quick formative assessment to make note of student learning as a result of the lesson.

Today's Exit Ticket asks students to describe the strategies they used to find the cost of one batch of cake pops? (Math Practice 2)