Salima Benkhalti
Matthew Brooke
Salima Benkhalti
Water Symposium Project
Title:
Daily Water Usage in the United States
Introduction:
The United States has a supply of fresh water equal to 600 billion gallons of water a day. This is equal to 3% of the world’s total supply. First let’s look at the word billion. What does this mean to you? Think about it this way; 1+9=10: 10+90=100: 100+900=1,000 (thousand): 1,000+9,000=10,000 (ten thousand): 10,000+90,000=100,000 (one hundred thousand): 100,000+900,000=1,000,000 (one million): 1,000,000+9,000,000=10,000,000 (ten million): 10,000,000+90,000,000=100,000,000 (one hundred million): 100,000,000+900,000,000=1,000,000,000 (one billion) and that is how we reach one billion. So when we look at the number 600 billion gallons of water a day we can see it as
59,000,000,000..
+1,000,000,000
=60,000,000,000 or 60 billion. This is a large number.
Objective: The United States has a supply of fresh water equal to 600 billion gallons of water a day. Below is a picture of ONE GALLON OF WATER. Now can you visualize 600 billion of these water jugs that are used daily in the United States!
One-gallon water jug weighs 8.65 pound. 600 billion gallons of water weighs 519,000,000,000 (519 billion) pounds. A car usually weighs about 2 tons, which equals to 4,000 pounds. Find how many cars would equal 519 billion pounds?
Now we can visualize the number 60 billion, let us look at the water usage in the United States in the last 20 years. We will be looking at daily water usage per day in the United States.
Facts and questions:
In 1960 on average the United States used 270 billion gallons of water per day
In 1970 on average the United States used 370 billion gallons of water per day
In 1985 on average the United States used 421 billion gallons of water per day
In 2000 on average the United States used 408 billion gallons of water per day
In 2005 on average the United States used 405 billion gallons of water per day
DATA FROM:http://pubs.usgs.gov/circ/1344/ andhttp://pubs.usgs.gov/circ/2004/circ1268/htdocs/text-trends.html
As we can see, there has been a decrease in water usage for the United States because of the recent awareness in the last 25 years (programs supporting a “go green” attitude for example). Use this data to predict the average water use in the United States in 2030, 206, 2075, 2090, and 2105. Will we ever reach 100 billion gallons of water per day if this steady decrease continues? If so, when?
One possible way to do this: From 2000 to 2005 there was a steady decrease in water usage of 10% or 0.1. So, from 2005 to 2010 the water usage for the United States would be 405 x 0.1 = 40.5 then 405 – 40.5 = 364.5. From 2010 to 2015 the water usage would be 364.5 x 0.1 = 36.45 then 364.5 – 36.45 = 328.05. Then so on…
Students can also use scatter plots, line graphs, or absolute growth to solve the problem. They should be encouraged to solve the problem in their own way.
Reflection questions:
Today in the world, we overlook many things that are happening around us and take a lot for granted. If we all could sit back and realize how lucky we are to have clean running water, then maybe we can start to change the way we use water. When you are brushing your teeth, turn off the water. Try to take a 3 to 5 minute shower instead of a 15 to 20 minute shower. Try to drink tap or filtered water instead of bottle water all the time. There are numerous things we can do to cut the water usage in the United States and all it takes is a couple kids to stand up and say, “I want to change this world for the better!”
Something to think about: How can you and your family be more efficient with your water usage? Write one to two paragraphs.
Common Core Standards Expected for 6th Grade Students from the Lesson Above:
● Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations.
○ Find a percent of a quantity as a rate per 100 (e.g., 30% of a quantity means 30/100 times the quantity); solve problems involving finding the whole, given a part and the percent.
● Interpret and compute quotients of fractions, and solve word problems involving division of fractions by fractions, e.g., by using visual fraction models and equations to represent the problem.
● Fluently add, subtract, multiply, and divide multi-digit decimals using the standard algorithm for each operation.
● Recognize that a measure of center for a numerical data set summarizes all of its values with a single number, while a measure of variation describes how its values vary with a single number.
● Summarize numerical data sets in relation to their context.