##
* *Reflection: Connection to Prior Knowledge
Shopping and Pondering Pounds and Ounces - Section 2: Concept Development

This problem was SO fun. My students really loved the challenge of trying to calculate the weight of the groceries and what would go into each bag. One thing that struck me as I observed students in this problem, almost all students started the task by trying to calculate the total first, even though it was not the first question asked. At the end of the period I led a brief discussion about how to solve this problem by adding items to each bag and finding the total weight of each bag. Students seemed to realize that finding subtotals would possibly be easier and more efficient for this problem.

This lesson's strength is the rich math task students are engaged in. All students in my class, regardless of their abilities, liked this task and truly wanted to persevere. I had several students not finish and ask to stay in during recess to reach an answer. You can watch my reflection video below to hear more thoughts about this lesson.

*Perfect Productive Struggle*

*Connection to Prior Knowledge: Perfect Productive Struggle*

# Shopping and Pondering Pounds and Ounces

Lesson 8 of 13

## Objective: SWBAT convert between pounds and ounces and add and subtract whole numbers, mixed numbers and fractions.

## Big Idea: In this task, students will participate in an activity that helps them convert and add ounces and pounds.

*50 minutes*

#### Number Hook

*5 min*

I start this number trick by asking the students what weighs more- a pound of feathers or a pound of bricks?

I use this question as a gauge to help me determine which students are not solid in their understanding of weight. Students may answer a pound of bricks. This is due to confusion concerning the weight or attributes of the objects being measured rather than an understanding of standard units of measure.

*expand content*

#### Concept Development

*45 min*

To begin this lesson, I lead a brief discussion about how heavy a pound is and how heavy an ounce is. Students have had lots of experience with pounds and ounces. Based on an informal pre-assessment as well as a computer program my students use everyday, 98% of my students understand that there are 16 ounces in a pound. Students also have a good understanding that ounces are very light and that one pound is about the weight of a loaf of bread. Knowing this, I designed this lesson as a problem solving lesson in which students have an opportunity to apply this understanding.

I begin by showing students a grocery bag. Dramatically, I pull out some play food items. (These are items listed on the grocery shopping list sheet.) I tell students they are going on a shopping trip and these are the items they are going to buy.

Next I show student the grocery problem. I read through the problem with them and highlight the three different questions on the sheet. I do this so students understand that they are answering three different questions.

Then I give students two pieces of plain white paper. I tell students that they have the entire rest of the class time to work on this problem. One paper is for their work and calculations and the other is for their answers and paragraph in presentation form.

As students work, I circulate around the room observing and helping as necessary.

*expand content*

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- UNIT 1: Getting to Know You- First Days of School
- UNIT 2: Multiplication with Whole Numbers
- UNIT 3: Place Value
- UNIT 4: Understanding Division and Remainders
- UNIT 5: Operations with Fractions
- UNIT 6: Fraction Equivalents and Ordering Fractions
- UNIT 7: Division with Whole Numbers
- UNIT 8: Place value
- UNIT 9: Geometry
- UNIT 10: Measurment
- UNIT 11: Fractions and Decimals

- LESSON 1: Measurement Mania - Metric Relationships
- LESSON 2: I Mustache You to Measure!
- LESSON 3: Who needs a Shave? - Line Plots
- LESSON 4: Pencils, Bugs and Line Plots - Day 1
- LESSON 5: Pencils, Bugs, and Line Plots! - Day 2
- LESSON 6: Patterns with Perimeter and Area
- LESSON 7: Great Grams and Grahams
- LESSON 8: Shopping and Pondering Pounds and Ounces
- LESSON 9: Too Heavy? Too Light? Conversions!
- LESSON 10: Horrendous Soup - Capacity Conversions
- LESSON 11: Limited or Lots of Lemonade? - Customary Conversions
- LESSON 12: Mastering Measurement - Assessment
- LESSON 13: Question Creation