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 · World
How has the world's population grown since 1960?
The interactive chart needs JavaScript. The numbers are on the chart's page.
The world had 8.22 billion people in 2025, about 2.7 times the 3.02 billion of 1960. It passed 8 billion in 2023. Figures are mid-year estimates from the United Nations, which revises them as new censuses come in.
How to read this chart
Each point is the number of people alive in the world in the middle of that year, estimated by the United Nations. The axis starts at zero, so the height of the line shows the true size. Look at how steep the line is to see how fast the population grew.
Questions to discuss
- Judging from the chart, about how many years did it take the world to add its most recent billion people?
- Is the line getting steeper or flatter in recent years? What does that tell you about the growth rate?
- These numbers are estimates that the UN revises. Why is it hard to count every person on Earth?
Source: World Bank, World Development Indicators: Population, total (CC BY 4.0 (credit the World Bank)) · Data as of Dec 31, 2025
Open the chart and its numbersChart 2 of 3 · Wealth
How is U.S. household wealth divided?
The interactive chart needs JavaScript. The numbers are on the chart's page.
At the end of June 2026, the wealthiest 1% of U.S. households held 32.5% of all household wealth, the next 9% held 36.4%, the next 40% held 28.8% and the bottom 50% held 2.3%. In 1989 the shares were 22.8%, 38.0%, 35.7% and 3.5%. Wealth here is net worth: what households own (homes, stocks and mutual funds, pensions and retirement accounts, private businesses, cars and other belongings, bank deposits) minus what they owe (mortgages, credit cards, student and car loans). The Fed estimates each quarter by combining its Financial Accounts with its Survey of Consumer Finances, taken every three years, so the newest quarters are estimates that get revised.
How to read this chart
Each bar is one group of U.S. households' share of all household wealth, so the four bars add up to 100%. The groups are different sizes: the top 1% is one household in every hundred, while the bottom 50% is half of all households. Compare each group's share of wealth with its share of households.
Questions to discuss
- Which group holds the largest share of wealth? Is it the group with the most households?
- If wealth were split evenly, what share would the bottom 50% hold? How far is the chart from that?
- The takeaway gives the 1989 shares too. Which groups gained a share since then, and which lost one?
Source: Federal Reserve Board, Distributional Financial Accounts (Public domain (Federal Reserve Board; cite the Board as the source)) · Data as of Jun 30, 2026
Open the chart and its numbersChart 3 of 3 · Climate
How much has the US warmed since 1895?
The interactive chart needs JavaScript. The numbers are on the chart's page.
The contiguous US averaged 54.6°F in 2025. The warmest year since records began in 1895 was 2024, at 55.5°F. Through 2025, the dashed trend line, the straight line that best fits every year, rose about 0.18°F a decade, or 2.3°F since 1895, and warming had sped up to about 0.5°F a decade since 1970. Alaska and Hawaii aren't included.
How to read this chart
Each point is one year's average temperature across the lower 48 states, in degrees Fahrenheit. The axis doesn't start at zero, so a small rise looks steep: read the numbers on the axis, not the height of the line. The dashed line is the trend, the straight line that best fits every year; single years bounce above and below it.
Questions to discuss
- Find the warmest and coolest years on the chart. How many degrees apart are they?
- Why might one year be much cooler than the year before, even while the trend line keeps rising?
- The axis doesn't start at zero here, but bar charts always do. Why is that fair for temperatures but not for bars?
Source: NOAA National Centers for Environmental Information, Climate at a Glance (Public domain (U.S. government work)) · 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.