- Students will apply mathematics strategies of counting, adding, and subtracting decimal amounts to create change for a dollar.
- Students will be introduced to the economics of making change when shopping.
- Total Time: 0-45 Minutes minutes
- Coins for making change (one set per pair of students)
- U.S. Mint website to project images of coins (link: https://www.usmint.gov/news/image-library/circulating)
- A sheet listing 6 purchasing scenarios to act out (one per pair)
- A worksheet listing 3 scenarios to work out independently with space to write out math sentences (one per student)
- After introducing the students to the value of all currently circulating U.S. coins (including cents, nickels, dimes, quarters, half dollars and dollar coins), explain that the students will be exploring how to make change for a dollar.
- Explain that there are different ways to make change: either subtract the cost from the amount given or count up from the cost until they reach the amount given. Today you will be counting up.
- Ask one student to be the shopper and one to be the clerk to model the activity for the class. Explain that the shopper wants to purchase one pencil which costs 25 cents. Have the shopper give the clerk 1 dollar, and the clerk count aloud how much change to give back (have the clerk start at 25 cents and count out 50 cents, 75 cents, 1 dollar, giving back three quarters). Ask other students to be shopper and clerk and model another simulation for the class. Repeat until students grasp this concept.
- Provide the students with a sheet listing 6 different scenarios to act out in pairs.
- Once the students seem comfortable with making change, provide each student with 3 more scenarios to work out independently. Provide manipulatives to help the students visualize their work. Then have the students write out number sentences to show how they solved each problem.
Differentiated Learning Options
- Observe group interactions for comprehension of the lesson objectives.
- Assess each student's worksheet of math sentences for comprehension of the lesson objectives.
Common Core Standards
- 2.OA.2. Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20, eg, by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.
- develop and use strategies for whole-number computations, with a focus on addition and subtraction;
- develop fluency with basic number combinations for addition and subtraction; and
- use a variety of methods and tools to compute, including objects, mental computation, estimation, paper and pencil, and calculators.
Discipline: Mathematics Domain: K-2 Number and Operations Cluster: Understand meanings of operations and how they relate to one another. Grade(s): Grades K–2 Standards: In K through grade 2 all students should
- understand various meanings of addition and subtraction of whole numbers and the relationship between the two operations;
- understand the effects of adding and subtracting whole numbers; and
- understand situations that entail multiplication and division, such as equal groupings of objects and sharing equally.
Discipline: Mathematics Domain: K-2 Number and Operations Cluster: Understand numbers, ways of representing numbers, relationships among numbers, and number systems. Grade(s): Grades K–2 Standards: In K through grade 2 all students should
- count with understanding and recognize "how many" in sets of objects;
- use multiple models to develop initial understandings of place value and the base-ten number system;
- develop understanding of the relative position and magnitude of whole numbers and of ordinal and cardinal numbers and their connections;
- develop a sense of whole numbers and represent and use them in flexible ways, including relating, composing, and decomposing numbers;
- connect number words and numerals to the quantities they represent, using various physical models and representations; and
- understand and represent commonly used fractions, such as 1/4, 1/3, and 1/2.