Does it need the Shopify connection?

No. Without it the machine works from the store's product list pasted in and cuts files the store imports. With it on, the card creates the drafts and reads the catalog itself, and says what it did.

Will it publish for me?

It makes drafts freely and publishes a product only when you name it; a batch is listed first. That is the law on the face.

Where do prices come from?

From you, on the ladder or off it. The card never prints a price it was not given and the store's price is the only true one.

Can it attach the files?

No — that door is the app's and yours. It checks the app's list against the record by name and bytes, and the room's punch check proves a downloaded copy.

How the house's own ticket finds a product: the handle first, then a handle or title that carries exactly its words. The card runs the same reading on the store's list so the ticket is never surprised.

No. It is a card at your elbow — a person with a machine and, when you allow it, a connection. It stores nothing, runs no server and holds no key of its own.

THE INSTRUMENTS · Nº 779 · EDITION 1 · METHOD + MACHINE

LUND CARDS · THE INSTRUMENTSNº 779 PROPOSED

THE CARD AS TEXT · FOR EYES AND FOR MACHINES

THE NUMBERS CARD · the arithmetic seat · numbers by machine, never by memory

WAKES WHEN totals, tax, discounts, rounding and money; percent changes, averages and splits; dates, durations and deadlines; unit conversions

THE LOOP

NAME — say: "This is THE NUMBERS CARD." Ask what the work is and what it must agree with; those answers are the session's source of truth.
WRITE THE SUM — the inputs and the operation, in words.
RUN IT — `python3 scripts/reckon.py calc "..."`, `tax`, `untax`, `pct`, `days`, `add`, `units`.
ROUND ONCE — `python3 scripts/reckon.py round AMOUNT` at the end of each line.
SHOW THE WORKING — inputs, operation, result.
LEDGER — write the ledger line.

NEVER

arithmetic in the AI's head
floating-point money
a total with no working shown

THE SEAL 68 of 100 · EPIC · WITNESSED · MACHINE ABOARD · SELFTEST 10/10 · 10 TESTS · WITNESSED ON REAL WORK

IT CAN BE WRONG an AI reading a text file: it can be wrong; check what matters. THE-CLAUSES.md rides in the packet and is part of the licence.

THE PUNCH · SHA-256 OF SKILL.MD · 940ED6AFA2C7ED8C0FA4D76C

THE FACE, FULL SIZE → · THE MACHINE FACE → · card.json →

THE NUMBERS CARD

the arithmetic seat · numbers by machine, never by memory

EXACT DECIMALS · ROUNDED LIKE A TILL · SHOW THE SUM

EPICWITNESSEDIN CLAUDE IN LUNDR IN CHATGPT

WITNESSED — the studio saw this card run and produce what its tin promises, and wrote the date down. What the marks mean →

THE SPEC SHEET · READ BEFORE YOU BUY · THE STANDARD EVERY CARD MEETS →

SEAL: 68 of 100 · EPIC · WITNESSED
EDITION: E1
MACHINE: scripts/ · 1 command · selftest 10/10
RUNS: On your own computer. Standard library only, offline; no account, no key, no telemetry.
HOSTS: Claude · Claude Code · ChatGPT · Gemini · any AI that reads a file (HOSTS.md names each door)
LICENCE: One person, any number of their own AIs and computers · editions replace files · nothing renews · freeze, not loss
PUNCH: 940ED6AFA2C7ED8C0FA4D76C · sha-256 of SKILL.md · check any file against it →

CITE THIS CARDTHE NUMBERS CARD, Edition 1. Lund Studio LLC, Westminster, Colorado. https://lundr.tech/?view=numbers-card. Punch 940ED6AFA2C7ED8C0FA4D76C. Retrieved 2026-10-10.

What it is.

A seat that never does arithmetic in its head: every figure that matters is computed exactly by machine, with the working shown.

Computes exactly in decimals, rounds like a till, works tax forward and backward, and handles percents, dates and units.

Its laws, written into the card.

Any number someone will act on is computed by machine, never by memory or mental arithmetic.
Money is exact decimals, never floating point, and rounded half up the way a till rounds — once, at the end of each line.
Show the working: the inputs, the operation, the result.
Tax works both ways: forward from an amount, and backward to the amount that lands exactly on a total — and when no amount lands exactly, say so.
A rate that can change is searched, not remembered.
Check the units before the arithmetic.

How it works, once your AI has it.

NAME — say: "This is THE NUMBERS CARD." Ask what the work is and what it must agree with; those answers are the session's source of truth.
WRITE THE SUM — the inputs and the operation, in words.
RUN IT — `python3 scripts/reckon.py calc "..."`, `tax`, `untax`, `pct`, `days`, `add`, `units`.
ROUND ONCE — `python3 scripts/reckon.py round AMOUNT` at the end of each line.
SHOW THE WORKING — inputs, operation, result.
LEDGER — write the ledger line.

When it says no.

Arithmetic in the AI's head.
Floating-point money.
A total with no working shown.

What’s in the buy.

CARD.md — the whole card · SKILL.md — the door your AI reads first · START-HERE.md — the first five minutes
AUDIT.md · CARD.md · HOSTS.md · LICENSE-NOTE.md · MANIFEST.md · MY-LEDGER.md · SKILL.md · START-HERE.md · THE-CLAUSES.md · TIN.md · WITNESS.md · card-machine.svg · card.html · card.json · card.svg · references/THE-METHOD.md · scripts/reckon.py · tests/EVALS.md · tests/evals.json · system/short-prompt.md · system/system-prompt.md — the packet as the cards chat cut it
MY-LEDGER.md · TIN.md · LICENSE-NOTE.md · THE-CLAUSES.md · card.svg + card-machine.svg + card.json · card.html · the doors for ChatGPT, Gemini, Cursor, Copilot and the rest, and an MCP door

PROOF · MACHINE ABOARD · SELFTEST 10/10 · 10 TESTS · WITNESSED ON REAL WORK · AUDIT 12/12 · EDITION 1 · PUNCH 940ED6AFA2C7ED8C0FA4D76C

ON EVERY DOOR · A CARD FOR YOUR AI, A FILE FOR YOUR COMPUTER

In Claude: turn on code execution under Settings › Capabilities, then Customize › Skills › + › Create skill, and upload the zip as it is — START-HERE.md in the box walks you through it, and tells you how to keep the ledger. In ChatGPT, Gemini and the rest: a Project, a GPT or a Gem with the card’s files attached and the short door in the box pasted as its instructions. The words run anywhere an AI reads Markdown; the machines run wherever the host runs Python. Witnessed in Claude only. The host marks →

Take it.

Nº 779 PROPOSED · ONE PAYMENT

Sold as is under the term printed. A card instructs an AI you operate; results depend on your model, your files and your judgement. Not legal, tax, medical or financial advice. The terms →

ONE PAYMENT · NOTHING RENEWS ITSELF

OFFLINE · ONE LICENCE · PUNCH-CHECKABLE · THE STANDARD

One payment. The file is yours to keep and keeps working at its edition; new editions issued in the year after you buy reach you by email as replacement files. Tax is added at checkout where it applies. Nothing auto-renews.

ONE PAYMENT — NOTHING RENEWS ITSELF. CHECKOUT IS SHOPIFY’S OWN; YOUR CARD COMES BY EMAIL AFTER IT.

← THE INSTRUMENTS · THE FLOOR →