Grade level: 5th grades

Skills: Multiplication (decimals)

Related environmental issues: Water

Area level: household

A typical conventional toilet uses 3.5 gallons of water in every flush. New water-efficient toilets use less water. For example, a low-flush toilet uses 1.6 gallons of water in every flush.

1.The average person in the United States flushes 5 times a day. How much water does it need when you have a conventional toilet and flush 5 times in a day?

2.How much water can you save in a day when you switch to a low-flush toilet?

3.How much water can you save in a week?

Source: Jenkins, Matt, 2014. A brief history of water conservation in America & Conserve H2O

———————————————————————————–

Answer keys

1.    17.5 gallons (3.5 x 5 = 17.5)

2.   9.5 gallons (3.5 – 1.6 = 1.9 1.9 x 5 = 9.5

3.   66.5 gallons (9.5 x 7 = 66.5)