Because of the wide differences in population among different countries, direct comparisons of numbers of cases, deaths, and tests among countries does not always provide a good understanding of how well each country is doing with respect to the pandemic. Making comparisons in terms of rates is a way to get a better understanding. Sometimes the rates are expressed as percent, sometimes as per 100,000 people, sometimes as per capita. You may use the information about Covid-19 provided by the New York Times (Links to an external site.) or use any other sources. In your report cite the sources and the day the information was consulted.
The United States is the third country in the world in terms of population size, so it is not surprising that there are more cases of Covid-19 in the U.S. than in other countries with smaller populations, such as Germany.
1) Using rates to compare the totals in the U.S., the world, and Germany (5 points)
Compare the population of the United States with the total population of the Earth as a percent. Compare the total number of Covid-19 cases in the U.S with the total number of cases in the world as a percent. Compare the number of deaths in the U.S. with the total number of deaths in the world. Do the same three calculations comparing Germany with the United Sates
Total Population (millions)
Covid-19 cases (millions)
2) Using rates for internal comparisons (5 points)
Express the number of cases in the U.S. as a percent of the population.
Express the number of Covid-19 deaths in the U.S. as a percent of the number of cases.
Find the number of Covid-19 deaths in the U.S. per 100,000 people.
Find a country that has fared better than the U.S. in these three aspects (it does not have to be the same country for all three). Find a country that has fared worse than the U.S. in these three aspects.
Country doing better (name)
Numbers for country 1
Country doing worse (name)
Numbers for country 2
Cases/population (as %)
Deaths/cases (as %)
Deaths/population (per 100,000)
3) Using rates for comparisons about testing (5 points)
Beyond closures and distancing, countries that have been successful dealing with the pandemic have paid attention to three aspects: testing, tracking, and treating. For this task we will focus in testing.
More testing will identify more cases, so an important piece of information is the percent of tests that give a positive result (meaning the person was infected). Find the percent of positive tests in the United States. Find the percent for two other countries, one with a higher percent and another with a lower percent.
Name of country
% positive tests
Because the same person can take the test several times and have a negative result several times, the percent of positive tests may underestimate the problem. Another rate that could provide better insight would be comparing the number of people whose tests turned positive for Covid-19 with the total number of people tested.
However, the total number of Covid-19 tests, and the percent of positive results, does not give a complete understanding how well a country is doing with respect to testing. Two other rates may provide additional insights. One is the number of tests as a percent of the total population. The other is comparing the number of tests to the total number of cases.
Compare the total number of tests in the U.S. with the total population (%). Compare the total number of tests in the U.S. with the total number of cases. Find two countries who are doing a better job in terms of testing in relation to these two measures.
Name of country
Number of tests/population
Number of tests/number of cases
Of course, the total number of cases and deaths does not give the whole picture about the seriousness of the pandemic. An important piece of information are the numbers of new cases and deaths. This information, however, is beyond the scope of this project.
4) Writing a report per team (10 points)
Write a brief summary of the situation of the pandemic in the United States. Use the information in other countries as points of reference. Make sure to use the proper units when reporting numbers (see the paragraphs about Principles of Unit Analysis, p. 73 in the textbook). Use the rates you computed in this task to illuminate and support your claims. The reporter will coordinate the writing and post the summary for your group in the whole class discussion, Task for Discussion Covid-19.
5) Feedback to other teams (5 points)
Choose a report from another team. Make suggestions for improvement (clarity, structure, voice, etc.) or select an aspect of their report that you found especially interesting, or that you would like to incorporate in your own report.
Bennett, J. & Brigs, W. (2019). Using and understanding mathematics (7th ed.). New York, NY: Pearson.
New York Times (2020). Coronavirus in the U.S.: Latest map and case count. Available (Links to an external site.)