Price tags · Puzzle #24 · Friday, October 23
Price tags: 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 Price tags.
1. Back-to-school shopping: How much were US families expected to spend on back-to-school shopping for K-12 students in 2026?
Photo: Leland Francisco from Dededo, Guam, CC BY 2.0 - Biggest category
- Electronics
- Grades
- Kindergarten through 12th
The answer: about $43.3 billion. It was a record, up from $39.4 billion in 2025 and the previous high of $41.5 billion in 2023.
Napkin math - 50MK-12 students in the US
- ×$600each on clothes, shoes, supplies and gadgets
≈$30B
The real answer is about $43.3 billion (National Retail Federation). On a napkin, take 50 million K-12 students in the US, times $600 each on clothes, shoes, supplies and gadgets, and you get about $30 billion. It's 1.4 times too low, which as a guess would still have scored 8.4 out of 10. The target is wider than it looks: every guess between $22 billion and $87 billion scores at least 7.0.
Source: National Retail Federation, Majority of Back-to-School Shoppers Get a Head Start on the Season
2. A day of Uber: How much did riders and diners spend through Uber on an average day in 2025?
Photo: Franklin Heijnen, CC BY-SA 2.0 - Counts
- Gross bookings, the full amount customers paid for rides and deliveries
- Users
- More than 200 million a month
The answer: about $530 million. Uber counted 13.6 billion trips in 2025, rides and deliveries together.
Napkin math - 200Musers a month
- ×4rides or deliveries each a month
- ×$20each
- ÷30days a month
≈$533M
The true figure is about $530 million (Uber Technologies). On a napkin, take 200 million users a month, times 4 rides or deliveries each a month, times $20 each, divided by 30 days a month, and you get about $530 million. That lands all but on the answer, worth 10.0 out of 10 as a guess. Because only the ratio counts, anything between $270 million and $1.1 billion was worth 7.0 or more.
3. Mercedes-Benz 300 SLR Uhlenhaut Coupé: What did Mercedes-Benz sell one of its two 1955 300 SLR Uhlenhaut Coupé prototypes for in an invitation-only auction in May 2022, in US dollars?
Photo: Guywelch2000, CC BY 4.0 - What
- One of only two 300 SLR Uhlenhaut Coupé prototypes, top speed 186 mph
- Sold
- Invitation-only auction at the Mercedes-Benz Museum, Stuttgart, with RM Sotheby's, 2022
The answer: $142 million. It became the most expensive car known to have been sold, and the money went to set up a Mercedes-Benz scholarship fund.
Napkin math: Top Ferrari 250 GTOs have sold for $50–70 million; the only one of two factory prototypes ever offered could plausibly double that.
The true figure is $142 million (CNN, as of May 2022). With no neat arithmetic to lean on, start with the order of magnitude: this one is in the hundreds of millions. Any guess from $71 million to $280 million scores 7.0 or better, because the game only counts how many times off you are.
Source: CNN, Mercedes just sold the world’s most expensive car for $142 million
4. Graduation gifts: How much were Americans expected to spend on graduation gifts in 2026, according to the National Retail Federation?
- Adults buying a grad gift
- 39%
- Top gift
- Cash
The answer: about $7.2 billion. That was a record, with cash the most popular gift.
Napkin math - 260Madults in the US
- ×0.4share who buy a gift
- ×$100each on grad gifts
≈$10.4B
The true figure is about $7.2 billion (National Retail Federation). On a napkin, take 260 million adults in the US, times 0.4 share who buy a gift, times $100 each on grad gifts, and you get about $10 billion. The estimate is 1.4 times too high, close enough to score 8.4 out of 10. Any guess from $3.6 billion to $14 billion scores 7.0 or better, because the game only counts how many times off you are.
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