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Students' assignment Worksheet

Answer key · for teachers

Charts to read and discuss

Figures as of November 14, 2026, from each chart's current data.

Chart 1 of 2 · Food and drug safety

How many food recalls are for salmonella each year?

The chart's answer: The FDA classified 77 food recalls for salmonella in 2025; the most since 2013 was 80 in 2016. Salmonella is a germ that causes food poisoning, often from eggs, produce, nuts, spices and pet food. 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 that names listeria too is counted on the listeria chart instead. Meat, poultry and most egg products are USDA's to recall and aren't included. The newest salmonella recalls, this year's included, are listed below.

Key numbers (Food recalls for salmonella)

Questions

  1. 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.

  2. Find the biggest change or difference in the chart. What might explain it?

    • 2013 to 2025: up 15 (+24%)
    • Biggest rise from one point to the next: 38, 2024 to 2025
    • Biggest drop from one point to the next: 24, 2018 to 2019
  3. Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?

    • Newest: 77 in 2025
    • Source: U.S. Food and Drug Administration, Enforcement Reports (openFDA food recall data), data as of November 4, 2026

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/salmonella-food-recalls-per-year

Chart 2 of 2 · Earthquakes

How much rarer is each step up in earthquake magnitude?

The chart's answer: In 2025 the world recorded 6,428 earthquakes of magnitude 4.5 to 4.9, 1,983 of magnitude 5, 129 of magnitude 6, 15 of magnitude 7 and 1 of magnitude 8 or more. Each step up in magnitude is roughly ten times rarer, and releases about 32 times more energy. Countless smaller quakes go unrecorded worldwide, so the chart starts at 4.5.

Key numbers (Earthquakes worldwide in the year)

Questions

  1. Roughly how many times more common is each band than the one above it?

    • 4.5 to 4.9 is about 6,428 times 8.0 or more
    • Highest: 6,428 (4.5 to 4.9)
    • Lowest: 1 (8.0 or more)
  2. The biggest bars are hard to compare with the smallest ones on this scale. What other way could you show these numbers?

    • Highest: 6,428 (4.5 to 4.9)
    • Lowest: 1 (8.0 or more)
  3. The chart starts at magnitude 4.5. Why might smaller earthquakes around the world go uncounted?

    Open question: answers will vary. Look for answers that use the chart's numbers and source.

Source: U.S. Geological Survey, ANSS Comprehensive Earthquake Catalog (ComCat) (Public domain (U.S. government work); source U.S. Geological Survey) · Data as of Dec 31, 2025 · chart.ly/charts/earthquakes-by-magnitude

More free charts and assignments at chart.ly/teachers