think-fermi-estimation SKILL.md skillA
think-fermi-estimation from product-on-purpose/thinking-framework-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add product-on-purpose/thinking-framework-skills/think-fermi-estimation@v0.1.0Pins v0.1.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- product-on-purpose/thinking-framework-skills
- Path
skills/think-fermi-estimation/SKILL.md- Versions recorded
- 5
- Latest version
- v0.1.0, committed Oct 21, 2026
- First version recorded
- Jun 2, 2026
- Size
- 8,817 bytes
- Repository stars
- 25
- License
- Apache-2.0
Produces a Fermi decomposition worksheet that estimates an unknown numeric quantity by factoring it into a chain of order-of-magnitude sub-estimates, guessing each to within a band, then multiplying back to a point estimate plus a compounded low/high range, with an independence check and a dominant-uncertainty flag. Use when you need a number and no lookup-able data or genuine reference class exists, so the magnitude has to be built from factors (for example sizing a market, a load, a cost, or…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
<!-- thinking-framework-skills | https://github.com/product-on-purpose/thinking-framework-skills | Apache-2.0 --> # Fermi Estimation Sometimes you need a number and there is nothing to look up: no dataset, no genuine reference class, no precedent to borrow. A single all-at-once guess at the whole magnitude is badly anchored and hides its own uncertainty. The Fermi move is to **factor the unknown into a short chain of sub-quantities** - each one small and familiar enough to guess to within a factor - then multiply the chain back into an estimate and compound the per-factor bands into a low/high range. The reason it can beat one wild guess is **partial error cancellation**: if the per-factor errors are roughly independent and centered, over-guessing one factor and under-guessing another tend to offset in the product. The output is a **Fermi decomposition worksheet**, not a lone number. The honest constraint: the cancellation only works when the factors are independent, and the benefit is real mainly for large, unfamiliar quantities - not ordinary ones you could estimate directly. ## When to Use …
Read the whole file at its exact version.
How to install
mdr add product-on-purpose/thinking-framework-skills/think-fermi-estimation@sha256:94b7704bb0652ae3The line at the top of this page pins the label v0.1.0, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_ewu63lvnel4mgxvu)
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Versions
The registry has recorded 5 versions of this file, between Jun 2, 2026 and Oct 21, 2026, about one every 35 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v0.1.0 latest | 2026-10-21 | d9425d5 | 8,817 B | A | view · diff |
| v0.1.0 | 2026-10-16 | 28965de | 8,315 B | A | view · diff |
| v0.1.0 | 2026-10-16 | 3b23394 | 8,218 B | A | view · diff |
| v0.1.0 | 2026-09-15 | 01156a8 | 8,199 B | A | view · diff |
| v0.1.0 | 2026-06-02 | c5c4a9c | 8,155 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (8817 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
product-on-purpose/thinking-framework-skills · 25 stars · license Apache-2.0 · pushed 2026-11-07 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_ewu63lvnel4mgxvu GET https://markdownregistry.com/api/v1/resolve?ref=product-on-purpose/thinking-framework-skills/think-fermi-estimation GET https://markdownregistry.com/api/v1/blob/94b7704bb0652ae31cef9c3019d7abc5b1e4e794a2d7c45a99d11a28f3376d04
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.