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Best Guess · Puzzle #24 · Friday, October 23

Best Guess: the answers

Four questions, each with one true number. Here they are with their answers, how to reason each one out, and where the number comes from. Play today's Best Guess.

  1. 1. How many marriages took place in the US in 2023?

    The answer: about 2.04 million. That is more than 5,500 weddings on an average day.

    Napkin math
    1. 330Mpeople in the US
    2. ÷80years a lifetime (about that many come of age each year)
    3. ÷2people a wedding

    ≈2.06Mmarriages

    The real answer is about 2.04 million marriages (CDC National Center for Health Statistics). To reason it out, take 330 million people in the US, divided by 80 years a lifetime (about that many come of age each year), divided by 2 people a wedding, and you get about 2.1 million marriages. That lands all but on the answer, worth 10.0 out of 10 as a guess. Because only the ratio counts, anything between 1 million marriages and 4.1 million marriages was worth 7.0 or more.

    Source: CDC National Center for Health Statistics, FastStats - Marriage and Divorce

  2. 2. How many pounds of butter did the average American eat in 2024?

    The answer: about 6.8 pounds. Butter is on the rise: Americans ate more in 2024 than in either of the two years before.

    Napkin math
    1. 52weeks a year
    2. ÷2weeks per stick of butter
    3. ÷4sticks to a pound

    ≈6.5pounds

    The true figure is about 6.8 pounds (USDA Economic Research Service). On a napkin, take 52 weeks a year, divided by 2 weeks per stick of butter, divided by 4 sticks to a pound, and you get about 6.5 pounds. That lands all but on the answer, worth 9.8 out of 10 as a guess. The target is wider than it looks: every guess between 3.4 pounds and 14 pounds scores at least 7.0.

    Source: USDA Economic Research Service, Dairy Data: Dairy products, per capita consumption, United States (annual)

  3. 3. On average, how many people used at least one Meta app (Facebook, Instagram, WhatsApp or Messenger) each day in June 2026?

    The answer: 3.60 billion. Meta calls this 'daily active people', and the figure was up 3% from a year earlier.

    Napkin math
    1. 8Bpeople on Earth
    2. ÷2people for each one on a Meta app daily

    ≈4Bpeople

    The real answer is 3.60 billion people (Meta Platforms, Inc.). Without looking anything up, take 8 billion people on Earth, divided by 2 people for each one on a Meta app daily, and you get about 4 billion people. The estimate is 1.1 times too high, close enough to score 9.5 out of 10. The target is wider than it looks: every guess between 1.8 billion people and 7.2 billion people scores at least 7.0.

    Source: Meta Platforms, Inc., Meta Reports Second Quarter 2026 Results

  4. 4. About how many ants are alive on Earth at any one time?

    The answer: about 20 quadrillion. Together these ants hold more carbon than all wild birds and mammals combined.

    Napkin math: Picture how many ants live under a single square meter of forest floor or grassland, then multiply by roughly 100 trillion square meters of land.

    The true figure is about 20 quadrillion ants (PNAS, as of 2022). There's no tidy chain of numbers for this one, so the skill is a sense of scale: the answer is in the tens of quadrillions. The target is wider than it looks: every guess between 10 quadrillion ants and 40 quadrillion ants scores at least 7.0.

    Source: PNAS (via Europe PMC), The abundance, biomass, and distribution of ants on Earth

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