Using Math To Make Environmental Decisions

To The Teacher: These problems are designed to help students understand that math is used in making real life decisions. The questions posed in the following situations are ones that businesses and people might realistically encounter. The numbers in these problems do not reflect actual costs but have been chosen based upon student instructional levels and needs. You may want to use these problems as part of math journals or integrate them into nonfiction writing assignments. They also lend themselves to cooperative learning groups and situations. If you are downloading these problems, you may choose to use the problem solving hints or you may want to delete these depending upon your student needs and your teaching purposes. The writing suggestions in the "Thinking About It" section are intended to help students use knowledge from a variety of subject areas to arrive at their own conclusions.

Name _________________________

Should the Richards Manufacturing Company Use Wind Power?

Maggie wants to help the owners of the Richards Manufacturing Company become more environmentally friendly. Right now they buy coal generated power. It costs the Richards Manufacturing Company \$1000 a month for its power. Maggie has helped them to find a company that sells wind power. For each wind generator that they install, the company will save \$150 per month on their power bill. But it will cost \$5,400 to buy each wind generator. If the Richards Manufacturing Company buys 3 wind generators, how many years will it take it to recover the amount of money it spent on converting to wind power?

To help you solve this problem, look at the words in bold and think about these things...

1. How much will the company save each month with 3 wind generators?
2. How much will the company save each year with 3 wind generators?
3. What figure in the story is really not important in helping you to make a decision?

How many years will it take the Richards Manufacturing Company to recover the amount of money it spent on changing to wind power?

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Do you think this is a good decision for the Richards Manufacturing Company to make?

Name _________________________

What Car Should Lilly Saylor Buy?

Maggie and her friend Lilly Saylor go car shopping. They find a car with an internal combustion engine (one that burns fossil fuel, gasoline). The car sells for \$18,660. It will cost Lilly \$115 each month to buy fuel and maintain this car. Lilly and Maggie also look at a fuel cell car. This car that is cleaner for the environment, costs \$22,400. It will cost Lilly \$65 each month to run and maintain this car. If Lilly is going to keep her new car for 5 years, how much will each car cost to buy and run over the 5 year period? Which car should Maggie advise Lilly to buy?

To help you solve this problem, look at the words in bold and think about these things...

1. How much will the internal combustion engine car cost to buy and run for five years?
2. How much will the fuel cell car cost to buy and run for five years?

What car is a better buy? _________________________________

Name _________________________

Can This Power Plant Be Built?

Phoebe Kasen is in charge of deciding whether a new power plant can be constructed. There is a camp for asthmatic children 50 miles from the site of the planned power plant. State regulations are that the amount of sulphur dioxide in the air cannot be more than 12 parts per million at the camp. If it is 12 parts per million or more, then the power plant cannot be built.

Phoebe finds that the testing equipment shows that the amount of sulphur dioxide in the air 20 miles from the plant will be 40 parts per million. 40 miles from the plant, the amount of sulphur dioxide will be 20 parts per million. At 80 miles from the plant the amount of sulphur dioxide in the air will be 10 parts per million.

Make a graph to show the relationship between the distance from the power plant and the amount of sulphur dioxide in the air. To help you solve this problem, look at the words in bold and study your graph.

Can this power plant be built?

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If you were Phoebe Kasen giving your report to officials from the power company and leaders of the camp for asthmatic children, what would you say? How would you present your information? Write a short speech.

Name _________________________

Should Dude Dog Food Company Install Energy Saving Windows?

The Dude Dog Food Company spends \$20,000 a year in air conditioning. They want to put in new windows that will help save money on this part of their power bill. The new windows will cost \$8,000 in total.

By adding these new windows, the company will save 10% a year on their energy bill. How long will it take the Dude Dog Food Company to recover the amount of money spent on the new windows by their energy bill savings?

How much is 10% of the current power bill?

How long will it take the Dude Dog Food Company to recover the amount of money it spent on the new windows by its energy bill savings?

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If you were the president of the Dude Dog Food Company, would you choose to install the new windows?

Name _________________________

What Should Matthew Orr Do?

Maggie's friend, Matthew Orr wants to start a mattress selling business. He has two options. He can rent a store and sell mattresses in the mini-mall. His other choice is to sell mattresses from a computer website and rent storage space. In both options, Matthew's customers will pay the delivery charge.

It will cost \$1,500 a month to rent a store and small storage space in the mini-mall. Matthew must hire many clerks, and salaries (the amount he has to pay each worker) will cost him \$5,500 each month if he opens a store. The mini-mall is a good location and Matthew will sell \$10,000 worth of mattresses each month from the store.

If Matthew sells mattresses from a computer website, he will not have to hire as many people. Salaries will only cost him \$2,000 each month. He will need to rent a warehouse and computer equipment, so that will cost Matthew another \$2,000 each month. He will not get as many customers on the website, so his mattress sales will be 20% less each month than in the store.

What advice should Maggie give her friend Matthew about how to sell mattresses?

To help you solve this problem, look at the words in bold and think about these things........

1. If Matthew opens a store, how many dollars worth of mattresses will he sell each year?
2. How much profit per year will the store make after Matthew pays store rent and salaries?
3. If Matthew sells mattresses on a computer website, how many dollars worth of mattresses will he sell each year?
4. How much profit per year will the computer website make after Matthew pays warehouse rent and salaries?

Your Final Answer... What will allow Matthew to make the most money?

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