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 · World
How fast has the world come online?
The interactive chart needs JavaScript. The numbers are on the chart's page.
73.6% of the world's people used the internet in 2025, up from 15.6% in 2005, the first year the World Bank gives a world figure. It counts people who used the internet at least once in the previous three months. The world figures are estimates by the International Telecommunication Union.
How to read this chart
Each point is the share of the world's people who used the internet at least once in the previous three months, as estimated by the International Telecommunication Union. The axis starts at zero, so the height shows the true share. The steeper the line, the faster people were coming online.
Questions to discuss
- About what share of the world was online in the first year on the chart, and in the latest year?
- Did the share grow faster in some years than others? What could have sped it up?
- Using the internet once in three months counts here. What does this number leave out about how people get online?
Source: World Bank, World Development Indicators: Individuals using the Internet (% of population) (CC BY 4.0 (credit the World Bank)) · Data as of Dec 31, 2025
Open the chart and its numbersChart 3 of 3 · Energy
Where does US electricity come from?
The interactive chart needs JavaScript. The numbers are on the chart's page.
In 2025 natural gas made 40.8% of US electricity, followed by nuclear (17.7%) and coal (16.6%). Wind made 10.5% and solar 6.7%. Solar counts only utility-scale plants, not rooftop panels, and the 2025 figures are preliminary.
How to read this chart
Each bar is one energy source's share of all the electricity made in the U.S. in a year, so the bars add up to about 100%. The bars start at zero, so a bar twice as long means twice the share. Solar counts only large power plants, not panels on rooftops.
Questions to discuss
- Which source makes the most electricity? About how many times more than the smallest bar?
- Which of these sources burn fuel and which don't? What share of electricity comes from each group?
- Why might a chart of this kind look different in your state than for the whole country?
Source: U.S. Energy Information Administration, Monthly Energy Review (Table 7.2a) (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.