Week 7 · Theme 1 Systems, Unit 1 Interactions of Organisms: Unit Project Build a Miniature Ecosystem and Interdisciplinary Project Waste Not, Want Not · 3 lessons
2
Where does our plastic go?
Discovery Education Science P5: Term 1, Unit 1, pp. 105–110
GoalDescribe how much plastic we throw away and why little of it is recycled.
New words
recycle · to make old things into new thingsreuse · to use something againreduce · to use less of something
Explanation
Plastic is cheap, light and strong, so we use a lot of it. Much of it is used once and thrown away. Only a small part is recycled. Why? Plastics come in many kinds, and they must be sorted before they are recycled. Dirty plastic is hard to recycle. Some kinds cannot be recycled again and again, and the plastic wears out. So recycling is not enough. Think of three Rs, in this order: reduce (use less), reuse (use again), then recycle. The best plastic is the plastic we never needed. At home we can say no to an extra bag, bring our own bottle and mend things instead of throwing them away.
reduce→reuse→recycle
Worked examples
Day
Bottles
day 1
3
day 2
2
days 3 to 7
5
total
10
Karim’s family counted the plastic bottles they used in a week. They used 3 on the first day, 2 on the second, and 1 each on the next 5 days. That is 3 + 2 + 5 = 10 bottles.
Bottles
recycled
3
thrown away
7
all
10
Suppose that out of 10 plastic bottles only 3 are recycled. The other 7 are thrown away. That is less than half.
Choice
Which R?
say no to an extra bag
reduce
fill a bottle again
reuse
sort bottles into a recycling bin
recycle
Which choice is better for the planet? Reducing comes first, because using no extra bag at all creates no waste.
Class activity
Three Rs poster. Draw three boxes: reduce, reuse, recycle. In each, draw one thing your family could do. Count the plastic bottles in your home recycling or rubbish for three days (look only, a grown-up handles the rubbish). Write the total. Which could you have avoided?
Practice
1
Give two reasons why little plastic is really recycled.
Any two: there are many kinds that must be sorted, dirty plastic is hard to recycle, some kinds wear out.
2
Put in order: recycle, reduce, reuse.
Reduce, reuse, recycle.
3
A family used 4 bottles on Monday, 3 on Tuesday and 5 on Wednesday. How many bottles in three days?
Day
Bottles
Monday
4
Tuesday
3
Wednesday
5
4 + 3 + 5 = 12 bottles.
4
Of 12 bags, 4 are reused. How many are not reused?
