shaft has torque = 34 ft lbfand
bullet has energy = 34 ft lbfto be added together even though they have the same units of measure.
Standard error is also built into the calculator based on a simple semantics for accumulation error. While not a substitute for careful error propagation analysis, it is a useful tool for keeping the realities of measurement visible.
The calculation engine can be accessed by defining a new truenumber as an expression involving other truenumbers. Or it can be used directly from any Truenumbers client application or via Truenumbers API’s. Some interesting examples of its capabilities are in the PDF below. You can download it with the tools at top right of the frame.