Chart assignment
Charts to read and discuss
Read each chart, then answer its questions. Every chart shows its source and date; open it for a table of the numbers and the data to download.
Chart 1 of 3 · Health
How long do Americans live, and how has that changed since 1900?
The interactive chart needs JavaScript. The numbers are on the chart's page.
A baby born in the US in 2018 could expect to live 78.7 years, up from 47.3 in 1900. The sharpest drop was in 1918, to 39.1 years, during the influenza pandemic. This CDC dataset stops at 2018; later NCHS reports put life expectancy at 78.4 years in 2023 and 79.0 in 2024, after a fall during the COVID-19 pandemic.
How to read this chart
Each point is how long a baby born in that year could expect to live, if death rates stayed as they were that year. It is an average, so it is pulled down a lot when many babies and young people die. Hover or tap a point to read its year and value.
Questions to discuss
- Find the sharpest drop on the chart. What happened in the world that year?
- Life expectancy in 1900 was under 50. Does that mean most adults died in their 40s? What else could lower the average?
- What changes in medicine, food or public health could explain the long rise?
Source: CDC National Center for Health Statistics, Death rates and life expectancy at birth (Public domain (U.S. government work)) · Data as of Dec 31, 2018
Open the chart and its numbersChart 2 of 3 · Wealth
What is the median household net worth by age?
The interactive chart needs JavaScript. The numbers are on the chart's page.
In the Federal Reserve's 2025 survey, the typical (median) household headed by someone under 35 had a net worth of $32,820, and one headed by someone 35 to 44 had $156,000. The median was $254,670 for ages 45 to 54, $411,340 for 55 to 64, $431,900 for 65 to 74 and $504,600 for 75 and over, about 15 times the under-35s'. The median is the household in the middle: half have more and half less. Averages are much higher, because a few households are very rich. Net worth is what a household owns (homes, retirement accounts, stocks, businesses, cars, bank accounts) minus what it owes (mortgages, student and car loans, credit cards). The survey is taken every three years, and figures are in dollars of the survey year. People of different ages also lived through different times, so this compares age groups, not one household's path through life.
How to read this chart
Each bar is the median net worth of households, grouped by the age of the person who heads them. Net worth is what a household owns, such as a home, savings and retirement accounts, minus what it owes, such as a mortgage or student loans. The median is the household in the middle: half have more and half have less.
Questions to discuss
- Which age group has the highest median net worth, and about how many times the under-35 group's is it?
- Why might net worth keep rising through most of a working life, and why might it fall for the oldest group?
- A few very rich households pull the average far above the median. Why is the median a better picture of a typical household?
Source: Federal Reserve Board, Survey of Consumer Finances (Public domain (Federal Reserve Board; cite the Board as the source)) · Data as of Dec 31, 2025
Open the chart and its numbersChart 3 of 3 · Earthquakes
How much rarer is each step up in earthquake magnitude?
The interactive chart needs JavaScript. The numbers are on the chart's page.
In 2025 the world recorded 6,428 earthquakes of magnitude 4.5 to 4.9, 1,983 of magnitude 5, 129 of magnitude 6, 15 of magnitude 7 and 1 of magnitude 8 or more. Each step up in magnitude is roughly ten times rarer, and releases about 32 times more energy. Countless smaller quakes go unrecorded worldwide, so the chart starts at 4.5.
How to read this chart
Each bar counts the earthquakes recorded worldwide in one year within a range of magnitudes. The bars start at zero. Each whole step up in magnitude releases about 32 times more energy, so a magnitude 7 quake is far more than one step stronger than a 6.
Questions to discuss
- Roughly how many times more common is each band than the one above it?
- The biggest bars are hard to compare with the smallest ones on this scale. What other way could you show these numbers?
- The chart starts at magnitude 4.5. Why might smaller earthquakes around the world go uncounted?
Source: U.S. Geological Survey, ANSS Comprehensive Earthquake Catalog (ComCat) (Public domain (U.S. government work); source U.S. Geological Survey) · Data as of Dec 31, 2025
Open the chart and its numbersTeachers: make your own chart assignment, or change this one. Free, no account needed.