For teachers. This answer key isn't linked from the students' page or worksheet; keep this link to yourself or share it with colleagues. Its numbers are the charts' current data, so they match what students see today.
Answer key · for teachers
Figures as of November 12, 2026, from each chart's current data.
Chart 1 of 3 · Food and drug safety
The chart's answer: The FDA classified 190 food recalls in 2025 for an allergen left off the label, such as milk, peanuts, tree nuts, wheat, soy, eggs, fish, shellfish or sesame; the most since 2013 was 282 in 2017. From 2013 through 2025, undeclared allergens were the most common reason food was recalled. A recall counts once however many products it covers, in the year FDA first listed it in its weekly Enforcement Report. Chartly sorted FDA's written reasons by their key words; a recall for a germ as well counts under the germ. Meat, poultry and most egg products are USDA's to recall and aren't included. The newest allergen recalls, this year's included, are listed below.
In one sentence of your own, what does this chart show?
Open question: answers will vary. Look for answers that use the chart's numbers and source.
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. Food and Drug Administration, Enforcement Reports (openFDA food recall data) (Public domain (U.S. government work); source U.S. Food and Drug Administration, openFDA) · Data as of Nov 4, 2026 · chart.ly/charts/food-allergen-recalls-per-year
Chart 2 of 3 · World
The chart's answer: 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.
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?
Open question: answers will vary. Look for answers that use the chart's numbers and source.
Source: World Bank, World Development Indicators: Population, total (CC BY 4.0 (credit the World Bank)) · Data as of Dec 31, 2025 · chart.ly/charts/world-population
Chart 3 of 3 · Crime
The chart's answer: In 2025 St. Louis, MO had the highest murder rate of the 89 biggest U.S. cities whose police reported a full year to the FBI, about 51.3 per 100,000 people, followed by Memphis, TN (31.0) and Cleveland, OH (28.0). Irvine, CA (0.0) and Plano, TX (0.7) had the lowest; the U.S. rate was about 4.4. Departments that didn't report a full year are left out (for 2025, New Orleans, Orlando and St. Petersburg, Florida). Each rate is per person the department serves, and a few, such as Las Vegas, Honolulu, Jacksonville and Louisville, serve their whole county. A city's rate also depends on where its borders fall, so compare cities with care.
How many cities on the chart have a murder rate above the U.S. rate, and how many are below it?
Open question: answers will vary. Look for answers that use the chart's numbers and source.
Why does a chart like this use murders per 100,000 people instead of the total number of murders in each city?
Open question: answers will vary. Look for answers that use the chart's numbers and source.
A city's rank can jump from one year to the next. Why might small numbers make rates bounce around?
Open question: answers will vary. Look for answers that use the chart's numbers and source.
Source: FBI Crime Data Explorer, Uniform Crime Reporting Program (Public domain (U.S. government work); source FBI Uniform Crime Reporting Program) · Data as of Dec 31, 2025 · chart.ly/charts/murder-rate-by-city
More free charts and assignments at chart.ly/teachers