The Strontium-90 Scenario

In all six sections of college-prep Algebra II (taught by three teachers, with two sections apiece), we have just completed a project in which each student has to understand a scenario (written by one of my colleagues), complete some mathematics with exponential and other functions, and use the mathematics to support a political argument:

Protect the Earth, an environmental advocacy group, has just offered you a short-term contract. Coincidentally, an energy corporation, Mr. Burns Inc., has made a similar offer. Each employer is willing to pay you $2000 for two weeks of part-time work! You will have to decide which to accept.

The money’s the same, so you want to know what the responsibilities are. Surprisingly, they seem to be the same for both jobs! Each employer wants you to get an interview with Senator Kerry to discuss a proposal by Mr. Burns Inc., which wants to get permission to dump 400 pounds of Strontium-90 into a vacant field in Weston. Strontium-90 has a half life of 28 years. The corporation is willing to provide a number of incentives in exchange for permission to dump the waste. These include paying Weston $5,000,000 for care of the dump site; a payment for each year thereafter of $10,000 less than the previous year’s amount; and free glow-in-the-dark bumper stickers with funny sayings such as “I’d Rather be Fission”, “Nuke-u-lar energy lights up my life”, and “I went to Three Mile Island and all I got was this lousy third eye.”

If you accept the Protect the Earth job, you will be arguing against Mr. Burns. If you accept his job, you will of course be arguing in favor of his offer.

Whichever job you take, it has two parts. First, make an advertisement to sway public opinion to your side. It could be a PowerPoint presentation, a video, a pamphlet, a newspaper ad, or a letter to the editor. (Any other ideas must have prior approval from your teacher.) Second, hold an interview with Senator Kerry. (Since he may be unavailable, a Weston teacher might take his place.) The senator or the teacher will have some specific questions for you to answer, so you need to be prepared!

Part One must include the following information, showing all computations and any other work. (Think carefully about a useful time frame and scale.)

  • An appropriate graph displaying the amount of Strontium-90 with respect to time.
  • An equation that will let you compute the amount of Strontium-90 after n years.
  • An appropriate table showing the amount of Strontium-90 with respect to time.
  • An equation and table that represent the payments from Mr. Burns Inc.
  • The exact amount of Strontium-90 when the payments from Mr. Burns Inc. run out.
  • The exact number of days when the Strontium-90 reaches 10 pounds in weight.
  • The percent decrease between the years 2009 and 2029.
  • The percent decrease between the years 2209 and 2229.
  • A clear explanation of how any or all of these support your argument.

After handing in Part One, each student was interviewed by a Senator Kerry surrogate: a Weston High School math teacher other than the student’s own teacher. What was particularly interesting was that we managed to get most of the department participating in the interviewing. It’s all too rare in the culture of schools for teachers to have anything to do with their colleagues’ students, since we all tend to close the classroom door and teach within our own castles. So it was a great experience for my students to be interviewed by teachers other than myself, and it was a great experience for those teachers to see what we’re doing in Algebra II and to see how well these sophomores and juniors can (or cannot, as the case may be) explain their conclusions in their projects.

After I finish reading and grading the projects, I will let you know how they turned out.



Categories: Math, Teaching & Learning, Weston