An article from NPR came in a touch to late to get credit. It analyzed data from the U.S. Census and reports that babies of color are now the majority. Sadly for NPR, my students broke that story months ago.
Enter the population project
When we learn new models, we like to know why they matter. In this activity, students analyze data from the U.S. Census from 1900-2010. It challenges them to:
- determine what function best models the growth of a population–linear, exponential, quadratic, or logarithmic
- use their models to predict what the U.S. population will look like in the future
Students found the activity fascinating and some of the results utterly surprising. As always, they appreciated the chance to apply their mathematical skills to something they care about, especially when given the chance to discuss the implications of their findings in small groups and classwide. (If you’re up for a powerful discussion, the data opens the door to big, somewhat less math-centric discussions.)
Find the activity here, Applying a Model – Population Project, and the data here, U.S. Census Data 1900-2010. Here’s how it works.
Implementation
Stage 1
Students begin by breaking into teams, then selecting one sub-population to analyze–American Indian, Asian / Pacific Islander, Black, Hispanic, or White (non-Hispanic). In this phase, each team’s goal is to plot its population’s growth from 1900-2010, then determine what function best models that growth–linear, exponential, quadratic, or logarithmic. (I have each team plot and analyze the data using Microsoft Excel or Google Sheets.) Each team concludes by hypothesizing why its model might have worked the best, then comparing its findings to the rest of the class. As a class, we discuss which models worked best for each population, then predict what implications our findings have for the future of the U.S. population. Tip: This is a great time to discuss the inevitability of exponential functions overtaking linear functions.
Stage 2
In the second stage, every team analyzes the same data. Here, they compare the growth of all non-White populations to the growth of the White (non-Hispanic) population. Rather than plotting and analyzing one set of data, now they plot and analyze two. Once they’ve built models for the growth of the non-White and White (non-Hispanic) populations, they use their lines of best fit to predict when the non-White and White (non-Hispanic) populations will match each other.
With the right scaffolding, I found that every student was able to take on even the most challenging questions this project posed. If you want to give your students time to explore these questions on their own, it’s a push to do this in a single day unless you have a 90 minute class.
Let me know if you have any questions, suggestions, or requests!