Best Guess · Puzzle #21 · Tuesday, October 20
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. How big was the median new single-family home completed in the US in 2025, in square feet?
The answer: 2,142 sq ft. Half of the 1,005,000 new single-family homes finished in 2025 were bigger than this, half smaller.
Napkin math - 8rooms in a house
- ×15feet long
- ×15feet wide
≈1,800square feet
The answer comes to 2,142 sq ft (U.S. Census Bureau). On a napkin, take 8 rooms in a house, times 15 feet long, times 15 feet wide, and you get about 1,800 square feet. The estimate is 1.2 times too low, close enough to score 9.2 out of 10. Any guess from 1,100 square feet to 4,300 square feet scores 7.0 or better, because the game only counts how many times off you are.
Source: U.S. Census Bureau, Highlights of 2025 Characteristics of New Housing
2. How many pounds of cheese did the average American eat in 2024?
The answer: about 39.5 pounds. Cheeses other than the American types (like cheddar) make up the larger share.
Napkin math - 1.5ounces of cheese a day (a slice or two)
- ×365days a year
- ÷16ounces in a pound
≈34.22pounds
The real answer is about 39.5 pounds (USDA Economic Research Service). To reason it out, take 1.5 ounces of cheese a day (a slice or two), times 365 days a year, divided by 16 ounces in a pound, and you get about 34 pounds. It's 1.2 times too low, which as a guess would still have scored 9.4 out of 10. Any guess from 20 pounds to 79 pounds scores 7.0 or better, because the game only counts how many times off you are.
3. How many times does an adult blink in an hour?
The answer: about 720 blinks. Each blink lasts only about a third of a second.
Napkin math - 3,600seconds in an hour
- ÷4seconds between blinks
≈900blinks
The real answer is about 720 blinks (PLOS ONE). To reason it out, take 3,600 seconds in an hour, divided by 4 seconds between blinks, and you get about 900 blinks. The estimate is 1.3 times too high, close enough to score 9.0 out of 10. Any guess from 360 blinks to 1,400 blinks scores 7.0 or better, because the game only counts how many times off you are.
4. About 5.8 million dogs and cats entered US animal shelters and rescues in 2025. How many dogs and cats were adopted?
The answer: about 4.2 million. Dog adoption rates rose to 57% in 2025, while cats held at 63%.
Napkin math - 5.8Manimals entering shelters
- ×2adopted out of
- ÷3animals coming in
≈3.87Mdogs and cats
The answer comes to about 4.2 million dogs and cats (Shelter Animals Count). Without looking anything up, take 5.8 million animals entering shelters, times 2 adopted out of every 3 animals coming in, and you get about 3.9 million dogs and cats. It's 1.1 times too low, which as a guess would still have scored 9.6 out of 10. The target is wider than it looks: every guess between 2.1 million dogs and cats and 8.4 million dogs and cats scores at least 7.0.