Tip & Bill Split Calculator implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t5-072

Effect

Computation or source lookup only

Input and validation requirements

The calculator has an unhandled undefined-result trap when number_of_people is zero: per_person requires division by zero. It should reject that input. The tip-percent convention is also ambiguous unless the interface explicitly states whether 20 means 20% or a decimal rate of 20.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "bill": 84.5,
    "tip_percent": 20,
    "num_people": 4,
    "tip_percent_interpretation": "20 percentage points = 0.20"
  },
  "expected_outputs": {
    "tip_amount": 16.9,
    "total": 101.4,
    "per_person": 25.35
  },
  "working": "tip = 84.50 × 0.20 = 16.90; total = 84.50 + 16.90 = 101.40; per_person = 101.40 ÷ 4 = 25.35."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche5/tranche5-results.json