Alexander’s Coin Conundrum

Summary

Using Judith Viorst's book Alexander, Who Used to Be Rich Last Sunday as a reference, students use several computation techniques to calculate how Alexander spends all of his money in no time at all.

• Dollar
• None

• N/A

Objectives

To achieve the standard of whole number computation, students will:

• Construct number meanings through real-world experiences and the use of physical materials
• Understand our numeration system by relating counting, grouping, and place value concepts
• Interpret the multiple uses of numbers encountered in the real world
• Model, explain, and develop reasonable proficiency with basic facts and algorithms
• Use a variety of mental computation and estimation techniques
• Use calculators in appropriate computational situations
• Select and use computation techniques appropriate to specific problems and determine whether the results are reasonable.

• Math

• 3rd
• 4th
• 5th

Class Time

• Sessions: One
• Session Length: 20-30 minutes
• Total Length: 0-45 minutes

• Whole group
• Pairs

Coins

Materials

• 1 copy of the book Alexander, Who Used to Be Rich Last Sunday by Judith Viorst
• 11-by-17-inch paper (one sheet per pair of students) folded or divided with lines into 10 boxes
• Pencils
• Play or real coins as manipulatives
• Calculators

Preparations

Fold or draw lines on the paper to create 10 boxes in which to calculate.

Lesson Steps

1. Read Alexander, Who Used to Be Rich Last Sunday aloud to your students.
2. Divide the class into pairs and give each pair a set of coin manipulatives. Tell the students that you are going to read the book again and stop whenever Alexander spends money so they can remove the number of coins he spends from their pile. When you've finished reading the book, check to see if any pair still has "unspent" coins.
3. Hand out a large (11" x 17") piece of paper (folded or divided into 10 boxes) to each student pair. Tell them that you will read the story again so they can record each transaction in a box.
4. Read the book again, stopping at each transaction so the students can record it on the paper. For example, have students write the amount of money Alexander receives from his grandparents in the first box. In the second box, have them calculate how much money Alexander has left after he buys all his gum. Continue this way throughout the story until Alexander has spent his last 20 cents.

Enrichments/Extensions

Have students write and illustrate their own stories about spending a dollar or fifty cents.

Technology Extensions

If students have Web-publishing skills, have them transform their stories about spending (above) into online books.

Assess

Evaluate the calculations for whether the students were able to determine how Alexander spent his dollar.

Common Core Standards

Discipline: Math
Domain: 4.MD Measurement and Data
Cluster: Solve problems involving measurement and conversion of measurements from a larger unit to a smaller unit
Standards:

• 4.MD.1. Know relative sizes of measurement units within one system of units including km, m, cm, kg, g, lb, oz, l, ml, hr, min and sec. Within a single system of measurement, express measurements in a larger unit in terms of a smaller unit. Record measurement equivalents in a two column table.
• For example, know that 1ft is 12 times as long as 1in. Express the length of a 4ft snake as 48in. Generate a conversion table for feet and inches listing the number pairs (1, 12), (2, 24), (3, 36), ...
• 4.MD.2. Use the four operations to solve word problems involving distances, intervals of time, liquid volumes, masses of objects, and money, including problems involving simple fractions or decimals, and problems that require expressing measurements given in a larger unit in terms of a smaller unit. Represent measurement quantities using diagrams such as number line diagrams that feature a measurement scale.
• 4.MD.3. Apply the area and perimeter formulas for rectangles in real world and mathematical problems. For example, find the width of a rectangular room given the area of the flooring and the length, by viewing the area formula as a multiplication equation with an unknown factor.

National Standards

Discipline: Mathematics
Domain: 3-5 Algebra
Cluster: Analyze change in various contexts.
Standards:

In grades 3–5 all students should

• investigate how a change in one variable relates to a change in a second variable; and
• identify and describe situations with constant or varying rates of change and compare them.

Discipline: Mathematics
Domain: 3-5 Algebra
Cluster: Represent and analyze mathematical situations and structures using algebraic symbols.
Standards:

In grades 3–5 all students should

• identify such properties as commutativity, associativity, and distributivity and use them to compute with whole numbers;
• represent the idea of a variable as an unknown quantity using a letter or a symbol; and
• express mathematical relationships using equations.

Discipline: Mathematics
Domain: 3-5 Algebra
Cluster: Understand patterns, relations, and functions.