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Core mechanic / Estimation interview

Free core game

Fermi Estimation Review

Clarify an impossible-sounding quantity, choose a method, state assumptions, and defend a range instead of a magic number.

Last reviewed 2026-10-26

The estimation review asks for a quantity nobody can count directly: windows in a city, golf balls in a bus, or basketballs in a conference room. The player must narrow the scope, choose an approach, select assumptions, estimate components, and present a range with reasoning.

The legitimate objective is internal consistency: do the units agree, does the arithmetic support the selected range, and are the assumptions stated? The fictional employer adds its own absurd verdict, such as penalizing an estimate for excluding Microsoft Windows. A source note distinguishes the reported interview inspiration from the in-game corporate scoring.

This mechanic is part of the free core game. It does not require live data, external AI, or a calculator.

What it tests

  • Decomposing a question before calculating
  • Tracking units and orders of magnitude
  • Making assumptions explicit and defending uncertainty

Where to play it

This mechanic can appear in free job applications, campaign chapters, and deterministic daily challenges.

Fictional roles that use it