Use
of the book:
Teacher background on waste characterization: p.48-50
Teacher notes on activity: p.51-53.
Student instructions for activity: p.54-55
Data recording/Analysis questions: p.56-58
Materials
Needed:
per group:
Bag of trash (Note: Have several colleagues collect “clean” trash.
This means that containers are washed and food is placed into
separate plastic bags. This way, the activity is cleaner, we
can re-use the non-food items, and we can also compare different
people’s trash.)
Large trash bag (to be cut open),
scissors
7 plastic bags (grocery store type),
triple-beam balance,
bathroom scale (can get manage with less than one per group),
calculators (2)
per student:
goggles,
rubber gloves (2)
Copies:
p.54-55 back-to-back and laminated for directions
p.54-55 on overhead transparencies
p.56, 57, 58 back-to-back for participants
p.48, 56, 57 on overhead transparencies
Opening
Strategy: p.52
How many of you take the trash out at home? How many bags/containers
each week? Where does it go? What would happen if no one picked
it up? What types of things do you throw away in your garbage?
Procedure: p.54-55
1. Measure mass of entire bag of trash. Probably need to use
bathroom scale rather than balance. (If scale is in lbs, will
need to convert to metric – 2.2 lbs. = 1 kg.) Teach students
how to weigh themselves first, then get student + bag of trash
weight, then subtract student weight.
2. Cut open large trash bag. Spread out on floor.
3. Put on goggles and rubber gloves. Sort and classify trash.
Record on data sheet p.56.
4. Put each category in a plastic bag (get bag’s mass first).
Find each mass using the triple-beam balance. Record in data
table p.56. Remind students to subtract the mass of the plastic
bag.
5. Calculate the percent of total mass for each category:
mass of category X 100
total
mass
Discuss with students how you want them to round their percents.
Decide if calculators are allowed. If I allow calculators, I
require students to write
out the equation and show their work.
6. Plot your percent data on the bar graph p.57 in the “class” columns.
7. Answer questions p.57-58.
Note: I think it is optional to do steps #8-9 now depending
on your students’ prior knowledge about reusing, recycling,
composting at this time. If you do these steps now, you will
first need to discuss these terms (especially composting).
