Calculator

Arithmetic that behaves the way a pocket calculator does, including the awkward parts.

17 capabilities 2 sections reference specification

Build against it

# give your agent the catalog — no account, no install
claude mcp add provespec -- npx -y provespec-mcp

# then, from any agent session
spec_get(slug: "calculator")                → the capability tree
spec_checklist(slug: "calculator")          → the questions to answer
spec_grade(slug: "calculator", grades: [...])  → parity % + the gap list

# or just fetch it
curl https://provespec.com/catalog/calculator/spec.json

Grade every capability below as yes · partial · no · na, with a file reference as evidence. Whatever you leave ungraded counts as missing — the gap list is the work queue.

Or just paste this to your agent

Use the ProveSpec MCP server. Fetch the "calculator" spec with
spec_get, then walk spec_checklist and grade this repository against it —
one verdict per capability, each with a file reference as the note.
Call spec_grade with the results and give me the gap list as the plan.

If the server is not registered, add it first:
  claude mcp add provespec -- npx -y provespec-mcp

The specification

AI 12

Arithmetic

✓ Four operations with correct precedence + − × ÷
✓ Decimal input and display one decimal point per number
✓ Sign toggle, percent, square root
✓ Division by zero is an error state, not a crash cleared by C
✓ Floating-point display rounding 0.1 + 0.2 shows 0.3 documented precision

Sequence

✓ Repeated equals repeats the last operation 2 + 3 = = gives 8
✓ Operator replacement before an operand 2 + × 3 uses ×
✓ Chained operations evaluate left to right unless precedence applies

Memory

✓ M+, M−, MR, MC indicator when memory is non-empty

Editing

✓ Clear entry versus clear all CE / C
✓ Backspace removes the last digit

History

✓ Recent calculations recallable

UI 5

Display

✓ Current entry and the pending expression both visible
✓ Long numbers switch to exponent notation never overflow the display

Input

✓ Full keyboard support digits, operators, Enter, Escape, Backspace
✓ Button press feedback visual and via keyboard focus

Layout

✓ Responsive grid that stays reachable one-handed

Open in Parity → Download spec.json All 102 specs