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 2 · Federal budget
Who owns the US national debt?
The interactive chart needs JavaScript. The numbers are on the chart's page.
At the end of August 2026 the federal debt was $40.2 trillion. Other U.S. investors (banks, mutual funds, pension funds, state and local governments and people) held $18.5 trillion, 46%. Foreign investors held $9.33 trillion (23%), federal trust funds such as Social Security's held $7.76 trillion (19%), and the Federal Reserve $4.55 trillion (11%). Foreign holdings are Treasury's TIC estimate, partly at market value, and the U.S. share is what's left after the others, so the split is approximate.
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. Treasury Fiscal Data, Debt to the Penny; U.S. Treasury, TIC Major Foreign Holders of Treasury Securities; Federal Reserve Bank of New York, SOMA Holdings (Treasury data public domain (U.S. government work). The SOMA Holdings data is subject to the Terms of Use posted at newyorkfed.org; the New York Fed is not responsible for publication.) · Data as of Aug 31, 2026
Open the chart and its numbersChart 2 of 2 · 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.