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. How much has a gallon of gas cost in the US since 1990?
  2. Where does US electricity come from?

Chart 1 of 2 · Energy

How much has a gallon of gas cost in the US since 1990?

The interactive chart needs JavaScript. The numbers are on the chart's page.

Regular gas averaged $4.31 a gallon in October 2026. The monthly average peaked at $4.93 in June 2022 and was lowest at $0.92 in February 1999. Each point averages EIA's weekly survey of gas stations nationwide, taxes included, in dollars of the day, not adjusted for inflation.

Questions to discuss

  1. In one sentence of your own, what does this chart show?
  2. Find the biggest change or difference in the chart. What might explain it?
  3. Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?

Source: U.S. Energy Information Administration, Gasoline and Diesel Fuel Update (Public domain (U.S. government work)) · Data as of Oct 31, 2026

Open the chart and its numbers

Chart 2 of 2 · 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

Open the chart and its numbers

Teachers: make your own chart assignment, or change this one. Free, no account needed.