World Population Growth

The World Population Growth Project will give students an experience of using mathematics in the context of a real-world problem.  They will gain an appreciation of the value of mathematics concepts like functions and statistics, both of which are required components of the pre-calculus curriculum by state standards.  It will also provide them with an interdisciplinary study of a topic, which will include presentation, writing, and research in areas like ecology and ethics.  They will use math in a more natural setting, unlike the contrived word problems they see in their math texts.  Additionally, those who do not typically succeed in or enjoy math may find a hook into the project that they do not have in the traditional math class.  All students participating will be challenged to solve open-ended problems and to think about complicated human issues and examine their own beliefs and values.

      The World Population Growth Project will begin with an introduction to the problem, followed by benchmark lessons on data representation, mathematical relationships, and mathematical modeling.  Student groups will then use these skills as they research past population growth and create a presentation which will include a good graphical representation of world population data, a best-fit model of this data, and predictions about the future based on the model they choose.  This will be integrated with lessons on exponential and logarithmic functions, as they discover that most recently, the world population has grown exponentially.  Following the presentations of the students’ findings, the class will begin to think about why the population is growing exponentially and whether or not it will continue to grow in this manner.  There will be a pivotal lesson on carrying capacity, which is the idea that a finite space will only be able to support a finite population, and thus the earth’s population will not be able to continue increasing exponentially forever.  This will cause the students to begin thinking about the impact of such a rapidly growing population on the earth and on human life.  We will modify our model of population growth to the logistic equation, which accounts for this tapering off of growth at some point in the future.  Finally, the students will think about and research possible ways to address this problem, the values beneath each, and the advantages and disadvantages of each.  Each student will complete the project with a paper summarizing how the world population has grown, the limits on future growth, and one issue resulting from the nature of this growth and how they think it should be addressed.