National Numeracy Network > Teaching Resources > Quantitative Writing > Examples > Calculating Divorce Rates

# Calculating Divorce Rates

This material is replicated on a number of sites as part of the SERC Pedagogic Service Project

#### Summary

Unreviewed Activity submitted in preparation for the NNN Writing with Numbers Workshop

This assignment acquaints students with a variety of ways to calculate the likelihood of divorce. Often the mass media and other reports tend to report divorce statistics in less useful and occasionally useless ways. Students use Excel to calculate and observe trends in divorce rates for national data from 1900 - 2004. From the data, students discuss which of three rates is the best way to measure divorce and write a short 2-3 page paper on their selection and the usefulness of three media related articles that discuss divorce rates.

## Learning Goals

To complete this assignment, students must utilize rate calculation, graphing, and critical thinking skills along with the ability to concisely summarize divergent views on a given topic.

## Context for Use

This activity was designed for a sophomore level class in family sociology. The activity needs to be introduced prior to students working with the data and should require at least part of a class for discussion when the assignment is due.

## Description and Teaching Materials

This assignment acquaints students with a variety of ways to calculate the likelihood of divorce. Often the mass media and other reports tend to report divorce statistics in less useful and occasionally useless ways. There are four ways to calculate divorce rates. The first, often called the "apples and oranges" method involves calculating a ratio of the number of divorces to marriages occurring in a given year. This involves comparing two groups which have little in common as only very few divorces involve marriages formed during the same year. The second, called the crude divorce rate, involves looking at the number of divorces taking place within the entire population whether married, widowed, too young to marry or not. These are the two most commonly used statistics in the media and in official governmental data.

The final two provide a more precise measure of divorce but are used less often. The refined divorce rate is based on the number of divorces within all marriages existing at a given time and is a useful way to look at the chances of divorce occurring. The last approach follows the amount of divorce occurring among a cohort of people who marry during the same year over time. This is a useful way to track when divorce occurs after marriage and to compare the likelihood of divorce within different cohorts.

In this exercise students calculate and graph the "apples and oranges," crude, and refined divorce rates from raw data from 1900 to the present in five and ten year intervals. They will be asked to discuss the advantages and disadvantages of each method. Finally, they will read examples of how all four rates are used in the media.

Materials:

## Teaching Notes and Tips

Students have a tendency to identify the correct divorce rate from the spreadsheet data (refined divorce rate = number of divorces/number of existing marriages), but to select a different rate when responding to the articles provided. On the other hand, students used the articles to identify factors that are associated with divorce such as educational level, etc.

## Assessment

See attached pre-test. The post-test needs work.

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