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.

  1. Where does US electricity come from?
  2. How has the world's population grown since 1960?
  3. How fast are US prices rising?

Chart 1 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

  1. Which source makes the most electricity? About how many times more than the smallest bar?
  2. Which of these sources burn fuel and which don't? What share of electricity comes from each group?
  3. 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

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Chart 2 of 3 · World

How has the world's population grown since 1960?

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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

  1. Judging from the chart, about how many years did it take the world to add its most recent billion people?
  2. Is the line getting steeper or flatter in recent years? What does that tell you about the growth rate?
  3. 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

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Chart 3 of 3 · Inflation

How fast are US prices rising?

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The inflation rate was 3.7% in September 2026: how much consumer prices changed from the same month a year earlier. Each point makes that comparison, back to 1914, the first year BLS can compare. Inflation peaked at 23.7% in June 1920 and at 14.8% in March 1980; the 9.1% of June 2022 was the highest since 1981. Prices fell as fast as 15.8% a year in 1921 and 10.7% in 1932. BLS collected no prices in October 2025, during a lapse in federal funding, so that month and October 2026 are missing.

How to read this chart

Each point compares consumer prices in a month with the same month a year earlier. A value of 3 means things cost about 3% more than a year before; below zero means prices fell. The chart shows how fast prices change, not how high they are.

Questions to discuss

  1. Find two times when inflation was highest. What was happening in the country then?
  2. If inflation falls from 8% to 3%, are prices going down, or just rising more slowly?
  3. Find a stretch when the line is below zero. Why might falling prices be bad news for workers and businesses?

Source: U.S. Bureau of Labor Statistics, Consumer Price Index (CPI-U, all items) (Public domain (U.S. government work)) · Data as of Sep 30, 2026

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