Daily estimation puzzle

Fermi Answer Today

Three questions. Three surprising answers. Reveal each answer when you’re ready, then see how Fermi estimates it.

Fermi #663 questions

A little help for today’s big questions.

1QUESTION 1 OF 3

How many full moons have there been since Cleopatra died?

Reveal answer & explanation

Official answer

25,400

full moons

How to estimate it

Fermi’s official “Napkin math”

Start with how long ago Cleopatra lived. She knew Julius Caesar, so call it about 2,000 years. How many full moons in a year? About one a month, so 12.

Since Cleopatra
~2,000 yrs
Full moons a year
× 12
2,000 × 12
≈ 24,000

Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.

Source calculation & reference
Cleopatra dies (Britannica)
Aug 10 or 12, 30 BC
Days to Sept 15, 2026
≈ 750,600
Synodic month (NASA)
÷ 29.53 days
750,600 ÷ 29.53
≈ 25,400

Reference cited by Fermi: Encyclopaedia Britannica for the date of death · NASA for the 29.53-day synodic month

Full answer & compare your estimate
2QUESTION 2 OF 3

How many hands of blackjack are dealt in Las Vegas casinos every day?

A blackjack table

A blackjack table

A dealer's hand placing cards on a green blackjack table, with stacks of chips beside the dealt hands

Illustration from Fermi.gg

Reveal answer & explanation

Official answer

4,500,000

hands

How to estimate it

Fermi’s official “Napkin math”

Vegas has maybe 50 real casinos, each with about 30 blackjack tables. How many hands does one table deal in a day? Say 5 players each getting a hand a minute, busy about half the day.

Casinos in Vegas
≈ 50
Blackjack tables in each
× 30
Hands per table per day
× 3,600
1,500 × 3,600
≈ 5,400,000

Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.

Source calculation & reference
Blackjack tables in Las Vegas casinos, 2025 average (Nevada Gaming Control Board)
≈ 1,500
Hands dealt per hour at a table of 3 to 5 players (Kilby, Casino Operations Management)
× 330
Hours a table is actually dealing each day, the middle of a 6 to 12 hour range (our assumption)
× 9
1,500 × 330 × 9
≈ 4,500,000

Reference cited by Fermi: Nevada Gaming Control Board Monthly Revenue Report, December 2025 (Twenty One tables, twelve-month average) and Jim Kilby, Casino Operations Management (hands per hour)

Full answer & compare your estimate
3QUESTION 3 OF 3

What is the combined worldwide box office gross of every film Steven Spielberg has directed?

Steven Spielberg

Steven Spielberg

Steven Spielberg in a tuxedo and round glasses, smiling and holding up two Oscar statuettes

Illustration from Fermi.gg

Reveal answer & explanation

Official answer

11,000,000,000

dollars

How to estimate it

Fermi’s official “Napkin math”

Spielberg has been directing since the 1970s, so call it 35 films. What does an average one take around the world? The giants like E.T. and Jurassic Park each made close to a billion, and the quiet ones far less. Say $300 million apiece.

Films directed
≈ 35
Average worldwide gross
× $300,000,000
35 × $300M
≈ $10,500,000,000

Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.

Source calculation & reference
US and Canada, every film he has directed (Box Office Mojo, via Statista)
≈ $4.7 billion
Rest of the world
+ $6.3 billion
Worldwide (The Numbers: $10.97 billion)
≈ $11 billion

Reference cited by Fermi: The Numbers worldwide box office for Steven Spielberg as director · Box Office Mojo per-film grosses, aggregated by Statista

Full answer & compare your estimate

Fermi answer archive

Find a past question and explore the reasoning behind it.

Fermi #65
  1. 1.How many Hafþór "Thor" Björnssons would it take to lift the Eiffel Tower if the weight were split evenly between them?
  2. 2.How many M&M's would it take to refuel, calorie for calorie, every runner who finishes the Boston Marathon?
  3. 3.How many pet snakes are kept in England?
Fermi #64
  1. 1.How many times does the name "Harry" appear across all seven Harry Potter books?
  2. 2.What is the combined age of all of the ambassadors to the United Nations?
  3. 3.If everyone on Earth formed one giant human pyramid, with each row one person shorter than the row below, how many rows tall would it be?
Fermi #63
  1. 1.How many drives would it take Tiger Woods to golf the length of Central Park?
  2. 2.How much fuel does a Boeing 747 burn per hour at cruising altitude?
  3. 3.How much did the world spend on movie tickets in 2025?
Fermi #62
  1. 1.How many kiwifruit would it take to weigh as much as an adult North Island brown kiwi?
  2. 2.How many cigarettes are smoked worldwide every day?
  3. 3.How many people live north of the Arctic Circle?
Fermi #61
  1. 1.How many sprays does it take to empty a bottle of Chanel No. 5?
  2. 2.How far is the world record for the longest paper airplane throw?
  3. 3.How much did the 20 Premier League clubs pay in player wages in the 2024/25 season?
Fermi #60
  1. 1.How many words are in the Bee Movie script?
  2. 2.How many people worldwide live within 10 km (6.2 miles) of an ocean coast?
  3. 3.Czechs drink more beer per person than anyone else in the world. How much beer does the average Czech drink in a year?
Fermi #59
  1. 1.How many crew members work aboard Icon of the Seas, the largest cruise ship in the world?
  2. 2.How many chicken eggs are laid worldwide every day?
  3. 3.How many plates of sushi are eaten at conveyor-belt sushi restaurants in Japan each day?

Showing 7 of 65 puzzles

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Fermi.gg is a daily estimation game with three numerical questions. Start with a rough guess, break the problem into smaller pieces, and aim to get as close as possible. A new puzzle arrives at midnight New York time.

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