standard_description: Understand that the two digits of a two-digit number represent amounts of tens and ones. Understand the following as special cases:
- The numbers from 11 to 19 are composed of a ten and one, two, three, four, five, six, seven, eight, or nine ones.
- The numbers 10, 20, 30, 40, 50, 60, 70, 80, 90 refer to one, two, three, four, five, six, seven, eight, or nine tens (and 0 ones).
- 10 can be thought of as a bundle of ten ones — called a “ten.”
problem_activity: Narrative
The purpose of this activity is for students to analyze their completed food waste journals. Students begin the activity by sharing their food journal with a partner and discuss a few things they notice. Then they use the data from the journal and their experience with multiplying and dividing large numbers in this unit to estimate how much food waste they might produce in a month and in a year. They compare those results to the national average and discuss some possible reasons for the difference.
Launch
Groups of 2
“Share your food waste journal with a partner. As you look over your journals, what do you notice?”
“What is the same? What is different?”
Activity
10 minutes: independent work time
2 minutes: partner discussion
Student Facing
Use your food waste journal to answer the questions. Be prepared to share.
How many pounds of food waste did you or your family produce in a week?
If you produce about the same food waste each week as recorded in the food waste journal, how much would you produce in a month? In a year?
The average person produces 219 pounds of food waste per year in the United States. With your partner, discuss reasons for the differences between your data and the national average.
Student Response
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Activity Synthesis
See lesson synthesis


aligns: no