How Can I Make $.35? : Using our Knowledge of Coins to Build A Total
Lesson 7 of 11
Objective: SWBAT determine the coins necessary to make a total.
I start class by handing out an entrance ticket to students. I allow students 5 minutes to work on the entrance ticket. When finished, I go over the question with students, allowing at least one student to share his/her strategy for solving the problem.
I am at the grocery store and see the following items:
I decide the buy the cereal and the milk. How much money do I need?
This entrance ticket reviews the objectives from previous days and sets the stage for students to determine the coins they need to make a total since students may break the amount they need for the cereal and milk down into coins.
Introduction to New Material
Now I need to figure out how I can make $.62. On the bottom of your entrance ticket. I want you to draw the coins you would need to be able to afford the milk and the cereal.
I allow students 2-3 minutes to work. As students work, I circulate to check for understanding.
Turn and Talk: What coins do you need to be able to afford all three items? How do you know?
As students share, again I circulate to check for understanding and determine student strategies. Some students may start with the largest coin (quarter or half dollar), others might make a bar model, others might create the total using tens and ones (dimes and pennies).
When students are finished sharing, ask 2-3 students who have used different strategies to share out their answers and strategies. I reinforce that it is okay to have different strategies/answers - there are different ways of getting to the correct amount. In order to prove this, I ask students to "prove" their answer either by showing their work on the white board or using coin manipulatives.
As students share, I write their strategies on the board so that all students will be able to reference the strategies later on.
Now you are going to work in partners on a practice problem. You can use coin manipulatives to help you solve the problem.
I allow students to work in heterogenous pairs for 5-10 minutes. (Students may use coins to help them solve the problem if it helps them visualize the problem).
When finished, I bring students back together and have students share different ways that they solved the problem. As students share, I write the various ways to make $.89 cents on the board so that students can visualize the wide variety of ways to solve the problem.
I tier independent practice by my students' facility with money:
Group A (In need of intervention)
Group A will work with the teacher to determine how to build a total. This group will have access to coin manipulatives.
Group B (Right on track!)
Group B will work independently to determine how to build a total. They will be expected to find ONE way to build a total.
Group C (Extension)
Group C will work independently to determine how to build a total. They will be expected to find MORE THAN ONE way to build a total.
I bring students back to the carpet. I ask students to share their work and their strategies with a teammate. I ask students to share so that they can hear different ways to successfully solve this type of problem. Additionally, I purposefully pair students so students in the C group are sharing their strategies with students in the A group--thus these students are getting exposure to more complex strategies and ways to group coins.
If time permits, I ask one student from each group to share their work with the class.