How many non-native marine species were found in Galápagos islands?

Grade level: 6th grades

Skills: Percentage and addition

sRelated environmental issues: Biodiversity

The Galápagos islands, which lie in the equatorial Pacific, have long been recognized for their remarkable biodiversity and their large number of endemic species.  However,  the environment of the Galápagos islands started to change because many non-native species have been brought to the islands by human activity over the last 500 years.


A recent research identified 53 non-native marine species in the islands.

  1. The research showed that 93% of the 53 species were likely brought to the Galápagos Islands by ships. How many non-native marine species were brought by ships? Round to the nearest whole number.
  1. The Galápagos islands were first visited by Europeans in the 1500s. By the late 1960s, 2000–3000 people lived on the Islands. In a 2010, there were 25,000 residents and one-quarter million visitors annually. Together, how many residents and tourists a year are there in the Galápagos islands?


Answer keys

  1. 49 species (53 x 0.93 = 49.29)
  2. 275,000 (25,000 + 250,000= 275,000)


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