Last updated: July 9, 2020

Math Skill: Addition & Subtraction (2-digit numbers)

Science Skill: Earth Water

Grade level: 2nd3rd grades

Environmental Area: Water

Purpose: Understand how much water is consumed for daily activities and develop awareness of water conservation


It is estimated that it takes 530 to 1,320 gallons of water to produce one person’s daily food. Demand for food production have been increasing as global population grows, and has demand for water. In particular, the increase of beef consumption has become one of the dominant pressures on our water resources because it takes a lot of water to raise beef cows. A single cow eats thousands of pounds of crops during its lifetime, and it takes large amounts of water to grow the crops for the cows. According to a research, it requires 460 gallons of water produce 4-ounce beefsteak.

It is expected that the global meat consumption will double by 2050 (United Nations FAO). After all, global water consumption for agriculture is expected to increase by 19% by 2050 (UNESCO, P47).


Do you know that it takes 14 times more water to produce a beefsteak than an apple? (From Factful Math Problems 2020)

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The table on the right shows how much water is required to produce some of the foods we eat quite often, such as apples and pizzas. The table is created based on data obtained from the Water Footprintand the World watch Institute.

worksheet & answer key

Math Skill: Addition & Subtraction (2-digit numbers)

Using the table,  students are asked to compare two types of food to figure out which one requires more/less water to produce. Questions in problem A include “How much more water does it take to produce a bottled soft drink than a cup of milk?”


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