Estimation Gym

About Estimation Gym

Estimation Gym started as one game, Fermi Questions, and now holds four, each on its own card on the home screen. Every game gives one question a day, the same for everyone, with its own streak. The idea behind the number games is that you do not need to know the answer: you work it out roughly from things you do know.

Fermi Questions asks for a real-world quantity, such as how many key presses a pianist makes in a full concerto. World Records asks for the size of a record, the fastest, furthest or most of something. Both are scored in powers of ten: within a factor of two is a Bullseye worth 100 points, within ten times is Close for 70, within a hundred times is Ballpark for 40, and anything further is Off. You can type big numbers in scientific notation, like 3e12.

Historical Dates asks when something happened, and you enter a year, or a full date when the question asks for one, with a BC button for ancient events. The same four bands apply, but measured in years or days, and they widen when the sources only pin a date roughly, so a guess about the Great Pyramid is not judged as strictly as one about the fall of the Berlin Wall.

Crossword Clues gives one answer word a day and three cryptic clues for it, hardest first. Solving from the first clue scores 100, the second 70 and the third 40, and giving up scores nothing; each clue comes with an explanation of how it works. In the number games a hint halves the day's points without breaking your streak, and after answering you see how everyone else did. There is a practice pool that does not touch your streak, an optional daily reminder, and a history you can copy to another device. The site is free with no account, installs to a home screen, and its source code is published under the AGPL.

How to play Estimation Gym

1. Open Estimation Gym and pick one of the four games from the home screen.
2. In Fermi Questions or World Records, type your estimate of the number; scientific notation such as 3e12 works.
3. In Historical Dates, enter a year, or the full date when asked, using the BC button for dates before the common era.
4. In Crossword Clues, solve the word from the first cryptic clue, or bring out the second and third clue for fewer points.
5. See your band and points and how everyone did, then come back tomorrow for new questions in all four games.

Screenshots

Tips

• For a Fermi question, break it into parts you can guess, such as minutes in the piece times notes per second, and multiply.
• Only the power of ten matters much: a factor of two either way still scores a Bullseye, so do not agonise over the last digit.
• For a date, bracket it between events you know, such as the telephone in 1876 and powered flight in 1903.
• Read the explanation after each cryptic clue; the later clues show the same wordplay more openly, which teaches the tricks.

Questions