Adding Two Prices

Overview

This 30-minute lesson helps first graders practice adding the prices of two items using play money and a simple menu/flyer. Students work in pairs, reinforcing their addition skills aligned with Common Core standard 1.OA.C.5, focusing on addition within 20 without regrouping. The lesson uses hands-on activities and workbook exercises to build real-world math understanding.

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Common Core Standards

CCSS.MATH.CONTENT.1.OA.C.5
Relate counting to addition and subtraction (e.g., by counting on 2 to add 2).

• Use addition within 20 to solve word problems involving situations of adding to, putting together, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.

CCSS.MATH.PRACTICE.MP1
Make sense of problems and persevere in solving them.

CCSS.MATH.PRACTICE.MP4
Model with mathematics.

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Learning Objectives

By the end of this lesson, students will be able to:

• Add the prices of two items using objects or play money models.
• Write and solve simple addition sentences within 20 without regrouping.
• Collaborate with peers to complete addition problems from a workbook.
• Demonstrate understanding of addition as putting together using real-world examples.

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Materials Needed

• Play money (bills and coins) in denominations up to $1
• Simple menu or flyer with pictures and price tags for classroom items (priced $1-$10)
• Whiteboard and markers
• Addition workbook pages (focused on adding two numbers up to 20, no regrouping)
• Pencils and erasers
• Pair seating arrangements (2 students per pair, total 5 students in class — one group of 3 can be formed)

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Lesson Breakdown

1. Warm-Up (5 minutes)

• Activity: Quick Mental Math Counting
  • Teacher holds up flashcards with numbers 1-10 and asks, “If you have 3 apples and get 2 more, how many now?”
  • Students respond orally.
  • Reinforce using fingers or counting aloud (MP1).

2. Introduction & Modeling (7 minutes)

• Activity: Using Menu & Play Money
  • Teacher displays the menu/flyer and picks two items with prices (e.g., juice $3 and sandwich $4).
  • Student volunteers come up and “buy” these items by counting out play money bills and coins to find total price (e.g., $3 + $4 = $7).
  • Teacher writes the addition sentence on the board: 3 + 4 = 7.
  • Emphasize the idea of putting together two prices (MP4).

3. Guided Practice in Pairs (10 minutes)

• Activity: Pair Work with Menu and Workbook
  • Students sit in pairs. Each pair receives a menu/flyer and play money.
  • Teacher assigns 3 addition problems from the workbook related to adding two prices.
  • Students use play money to simulate buying those items and write out the corresponding addition sentences.
  • Teacher circulates, provides support as needed, and prompts students to explain their thinking.

4. Sharing & Discussion (5 minutes)

• Each pair shares one problem solution with the class.
• Students explain how they used play money and addition to find totals.
• Teacher writes varied solutions on the board to reinforce different approaches to addition.

5. Independent Check & Closure (3 minutes)

• Quick formative assessment:
  • Teacher gives each student a quick addition question orally (e.g., "If you buy an apple for $2 and a cookie for $5, how much do you pay?")
  • Students respond by either holding up the correct number card or writing answer on mini whiteboards.

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Differentiation

• For advanced learners: Challenge with three items instead of two for addition within 20.
• For learners needing support: Use physical counters (e.g., blocks) to count totals before connecting with written addition.

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Assessment & Reflection

• Formative assessment embedded via oral questioning and workbook completion.
• Observe students’ ability to connect play money count with written addition.
• Note students needing further practice and tailor next lessons.
• Reflection prompt for teacher: Did students demonstrate understanding of combining two prices? Which students struggled with the physical-to-numerical connection of addition?

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Teacher’s Tips

• Engage students by turning the activity into a mini “store” where they take turns being cashier and shopper.
• Use real-world contexts familiar to children to make abstract addition tangible.
• Encourage students to verbalize their thought process to deepen understanding.

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This detailed and hands-on lesson ensures students gain confidence adding two numbers in practical contexts, truly embodying the Common Core focus on applying addition to real-world situations.