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 · Inflation
How much does a dozen eggs cost in the US?
The interactive chart needs JavaScript. The numbers are on the chart's page.
A dozen grade A large eggs averaged $2.27 in September 2026. The record so far is $6.23 in March 2025; prices spiked in 2023 and 2025 when bird flu cut the number of laying hens. Prices are BLS averages across US cities since 1980, when this series begins, in dollars of the day, not adjusted for inflation. October 2025 is missing because a lapse in federal funding stopped data collection.
Questions to discuss
- In one sentence of your own, what does this chart show?
- Find the biggest change or difference in the chart. What might explain it?
- Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?
Source: U.S. Bureau of Labor Statistics, CPI Average Price Data (eggs, grade A, large) (Public domain (U.S. government work)) · Data as of Sep 30, 2026
Open the chart and its numbersChart 2 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 numbersChart 3 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 numbersTeachers: make your own chart assignment, or change this one. Free, no account needed.