Free practice · numeric · easy

Practice

Evaluate an order-total expression

Given price = 8, quantity = 3, and fee = 2, what is price * quantity + fee?

Typed expression trace

Every value has a type before an operator uses it

Source
Raw value and its current type
Contract
Allowed type, format, and range
Conversion
Explicit and failure-aware
Expression
Operators applied by precedence
Evidence
Resulting value and type

Track the source value, current type, conversion boundary, evaluation order, and resulting type instead of relying on how a value looks.