Do we recycle more plastic or less?

Grade level: 5th – 6th grades

Skills: Percentage

Related environmental issues: Recycling

Our county has been at a loss how to treat our plastic waste.  The United States used to ship 70% of our plastic waste to China to reduce plastic waste in our county. However, after China stopped accepting internaitonal plastic waste to protect their environment last year, less plastic is recycled because we generate more plastic waste than we can handle.

Plastic Waste Photo: National Geographic

Plastic Waste   Photo: National Geographic

  1. On average, 150 plastic bottles are consumed by a single person in the United States. Of which, 29% of the plastic bottles were recycled in 2017. How many plastic bottles were recycled per person in 2017 on average? Round to the nearest whole number.
  2. On average, how many plastic bottles were NOT recycled and ended up in landfills per person in 2017?
  3. Ben started using his water bottle and reduce his plastic bottle use to 100 bottles per year. If he recycles 29% of the plastic bottles as the average American does, how many plastic bottles will he send to landfills a year?
  4. Is the number of plastic bottles Ben sends to landfills larger or smaller than the U.S. average?



Answer keys

  1. 44 bottles (150 x 0.29 = 43.5)
  2. 106 bottles (150 – 44 = 106)
  3. 71 bottles (100 – 29 = 71)
  4. Smaller


How much has the weight of plastic bottles changed?

Grade level: 3rd – 5th grades

Skills: Division 

Related environmental issues: Reduce /  Reuse / Recycle

The average weight of  plastic beverage bottles has changed over time. In 1980, five empty 2-liter PET bottles weighed 340 grams.  Now, nine 3-liter PET bottles weigh 378 grams.


  1. Which weighs more, a plastic bottle in 1980 or now? And how much?
  2. Why do you think has the weight of plastic bottles changed? Explain.

Sources: PET Resin Association, Little-Known Facts about PET Plastic




Answer keys

  1. 1980 bottle: 340 ÷ 5 = 68 (g)   Now: 378 ÷ 9 = 42 (g)    68 – 42 = 22 (g)     A plastic bottle now is 22 g lighter than that in 1980.
  2. Answers may vary: Hint 1) Lightweight plastic bottles reduce the use of plastic and raw materials  2) Lightweight plastic bottles reduce overall weight of the item and reduce energy consumed and CO2 emitted in the process of manufacturing and transporting the item. 3) Lightweight plastic bottles reduce plastic (and raw materials) use, so does the amount of plastic that has to be recycled.