Add a two-digit plus two-digit number Since this is the first time money is introduced formally as a standard, students will need many experiences with coin recognition and determining the of coins before using to solve problems. These skills can be reinforced during morning meeting and throughout the school day. students have not been introduced to decimals, problems focus on whole dollar amounts or cents. Once students have a understanding of coin recognition and values, they can then begin using the values of coins to count sets of coins, compare two sets of coins, make and recognize equivalent collections of coins (same amount but different combinations if coins), select coins for a given amount, and make change. Materials Chart paper for recording ideas jar filled with pennies Resource Sheet 12: Hundred Chart (one copy per student) Resource Sheet 13: Counting by 5’s (two copies per group of 4 students) Resource Sheet 14: Counting by 10’s (two copies per group of 4 students) Red and yellow crayons (2 of each per group of 4 students) Money manipulatives or real coins (If virtual coins are available students should be allowed to use these as well.) Dry erase boards and dry erase markers (one per student) Math Journals Resource Sheet 15: Billy’s Coins (one copy per student) Resource Sheet 16: Piggy Bank Recording Sheet (one copy per student) A book about money to read aloud to the class, such as Judith Viorst’s Alexander Who Used to Be Rich Last Sunday, or Julie Glass’ A Dollar for Penny. Resource Sheet 17: Dollar Chart Resource Sheet 18: Get to a Dollar Bags that zip, filled with 30 pennies, 20 dimes, and 2 play dollars (one for each pair of students for the game ‘Get to a Dollar’) Bags that zip, filled with a combination of coins and bills that total between $5.00 and $10.00 (one for each student, for Activity 3)
Be Rich Last Sunday, or Julie Glass’ A Dollar for Penny. Allow time for students to respond to the story. Distribute bags of pennies, nickels, and dimes to each pair of students. Ask students how to make 25¢. students the opportunity to respond with ways to make 25¢. List their responses on chart paper. Ask students to remind you of a few different ways to write cents (using a symbol or using words). Keep the visible for students to use as a reference when playing the game Get to a Dollar. If no student responds by saying “a quarter,” introduce the quarter to students as a coin whose value is 25¢. Show students that two quarters=50¢, three quarters=75¢, and four quarters=one dollar. Distribute Resource Sheet 17: Dollar Chart. Discuss the chart with students. Ask them what patterns they see and how the chart could help them to count money. Introduce the game Get to a Dollar (Resource Sheet 18). Model how to play the game with student volunteers. Ask questions as students play, such as, “How much more do we need to get to a quarter? To a dollar?” using different properties of operations and objects.” SMP 5: Use appropriate strategically. “Mathematically proficient students consider the available tools when solving a mathematical problem. These tools might include pencil and paper, concrete models, a ruler, a protractor, a calculator, a spreadsheet, a computer algebra system, a statistical package, or dynamic geometry software. Proficient students are sufficiently familiar with tools appropriate for their grade or course to make sound decisions about when each of these tools might be helpful, recognizing both the insight to be gained and their limitations.” SMP 7: Look for and make use of structure. “Mathematically proficient students look closely to discern a pattern or structure.”
For a challenge, have students sort 15 dimes into four different groups so that each group has a different number of dimes. Students need to determine if zero is a group, and explain why. They will also need to decide if there is more than one answer, and how they know they found all possible groupings. Closure Ask the students to tell you everything they know about our money system. Record student responses on chart paper. Ask students where they see money used outside of school. Possible Exit Questions: How many different ways can I use coins to make 87¢? How many nickels does it take to make the same value as two quarters? Make a list of all the coins and their values. If you dropped a nickel a day into your piggy bank, how much money would you save in one week? In two? SMP 3: Construct viable arguments and critique the reasoning of others. “Mathematically proficient students understand and use stated assumptions, definitions, and previously established results in constructing arguments.” “Elementary students can construct arguments using concrete referents such as objects, drawings, diagrams, and actions. Such arguments can make sense and be correct, even though they are not generalized or made formal until later grades. Later, students learn to determine domains to which an argument applies. Students at all grades can listen or read the arguments of others, decide whether they make sense, and ask useful questions to clarify or improve the arguments.”