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.

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.

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.

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)

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.

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.

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?

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.

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.