Budgeting a Bake Sale: Math Lesson on Profit, Fractions & Percentages

Lesson Plan: The Entrepreneurial Kitchen - Budgeting a Bake Sale

Materials Needed:

• Calculator (optional, for checking work or focusing solely on conceptual understanding)
• Whiteboard or large paper pad/markers
• Fictional Recipe Card (with 4–5 ingredients and their store prices listed)
• Pencils/Paper/Ruler
• "Budget & Profit Tally Sheet" template (simple spreadsheet drawn on paper)
• Real or pretend money (optional, for visualizing calculations)

Learning Objectives (Tell them what you'll teach):

By the end of this lesson, you will be able to successfully run a miniature business simulation by applying basic math skills. You will be able to:

1. Calculate simple fractions (1/2, 1/4, 3/4) of money amounts.
2. Convert between simple percentages (25%, 50%, 75%) and decimals/fractions when dealing with discounts.
3. Determine the total cost of ingredients and calculate the final profit for a sale item.

Introduction (10 Minutes)

Hook: Start Your Own Business!

Educator Prompt: Imagine you want to save up for a specific purchase, and you decide to start a small bake sale business. You need to calculate exactly how much each item costs you to make so you don't accidentally lose money. Today, we are acting as the CFO (Chief Financial Officer) for our bakery!

Activity: Quick Warm-up Discussion (Real-World Relevance)

• If a chocolate chip cookie sells for $1.00, and it cost you 50 cents to make, how much profit did you make? (0.50)
• If we need to use half a block of butter that cost $4.00, how much did that butter actually cost the batch of cookies? ($2.00)

Success Criteria:

You are successful in this lesson if you can correctly fill out the Budget & Profit Tally Sheet, showing a clear, positive profit margin for our theoretical bake sale item.

Body: Content and Gradual Release (40 Minutes)

I DO: Modeling the Calculations (10 Minutes)

Concept Focus: Fractions and Percentages of Whole Numbers (Money)

1. Educator Demonstration: "Let's look at the first ingredient on our recipe card: Flour. The whole bag costs $8.00. Our recipe only requires 1/4 of the bag."
2. Modeling Fraction Calculation: "To find 1/4 of $8.00, we divide $8.00 by the denominator (4). $8.00 ÷ 4 = $2.00. So, the flour cost us $2.00."
3. Modeling Percentage/Decimal Calculation (Discount): "Next is Sugar. It costs $4.00, but the store has a 25% discount this week."
   • Fraction Link: 25% is the same as 1/4. So we find 1/4 of $4.00, which is $1.00.
   • Calculation: $4.00 (original cost) - $1.00 (discount) = $3.00 (actual cost).
   • Decimal Link (Scaffolding/Extension): We can also multiply $4.00 by 0.25 to find the discount, or multiply $4.00 by 0.75 (the remaining cost) to find the final price.
4. Transition: Now we will apply these methods to the rest of the recipe together.

WE DO: Guided Practice - Calculating Total Ingredient Cost (15 Minutes)

Activity: Collaborative Cost Calculation

The student and educator work together to calculate the costs for the remaining 3–4 items on the fictional Recipe Card, filling out the "Budget & Profit Tally Sheet" simultaneously.

Formative Assessment: The educator monitors the student’s setup of the division or multiplication problems. If the student struggles with the calculation, ask, "How else can we show 50%?" to reinforce the connection to 1/2.

YOU DO: Independent Application - Setting the Price and Calculating Profit (15 Minutes)

Activity: The Pricing Challenge (Choice & Autonomy)

1. Tally Total Cost: The student adds up the final "Cost to Batch" column. (Example: $10.50 total cost for 12 cookies).
2. Determine Unit Cost: The student divides the Total Cost by the yield of the recipe (e.g., $10.50 total cost / 12 cookies = $0.875 per cookie).
3. Set the Target Profit Margin: The student determines a target profit margin (e.g., "I want to make at least a 50% profit.")
4. The Pricing Calculation:
   • Student calculates 50% profit on the unit cost: $0.875 x 0.50 = $0.44 profit per cookie.
   • Student adds profit to cost: $0.875 + $0.44 = $1.315.
   • Student rounds up to a sensible selling price (e.g., $1.50 per cookie).
5. Final Profit Calculation: The student calculates the total potential profit based on selling all 12 items at $1.50 each.

Educator Support: Offer choices for rounding (e.g., "You calculated $1.315. Do you want to sell it for $1.25, $1.30, or $1.50? How does that affect your profit?")

Conclusion: Closure and Recap (10 Minutes)

Review & Reflection

Recap Questions:

1. If something costs $10.00 and you need 3/4 of it, how much money is that? (Learner must explain the steps: $10 ÷ 4 = $2.50, then $2.50 x 3 = $7.50.)
2. Why is it important to know your unit cost before setting a selling price in a business? (To ensure profit/avoid losing money.)

Summative Assessment: Final Tally Sheet Review

The educator reviews the completed Budget & Profit Tally Sheet. Check specifically for:

• Accuracy of at least two fractional calculations (Entry Level 3 requirement).
• Correct identification and application of a percentage discount.
• Accurate calculation of the final total cost and profit margin.

Differentiation and Adaptability

Scaffolding for Struggling Learners (Focus on Concept):

• Visual Aids: Use physical manipulatives (e.g., separating pretend coins or chopping a paper circle into quarters) to represent the division of the money amount.
• Calculator Use: Allow unrestricted use of the calculator for complex multiplications, shifting the focus entirely onto the conceptual setup (knowing whether to multiply by 1/4 or 0.25).
• Simplify Fractions: Only work with halves (50%) and quarters (25%) throughout the lesson.

Extension for Advanced Learners (Focus on Complexity):

• Advanced Fractions/Ratios: Introduce ingredients that require 1/3 or 2/5 of the bulk item.
• Tax/Variable Costs: Add a variable cost element, such as 7% sales tax on the initial ingredient purchases, and have the student incorporate that into the final budget.
• Scaling the Recipe: Challenge the student to recalculate the budget if they needed to triple the recipe batch size.