Patent US 5,138,566

A Production Pal is provided that permits a user to perform calculations directly upon fractional data. Input to the Production Pal can be either a length expressed as a mixed fraction or rectangular measurements (length.times.width). The desired size, original size, and scaling factor (decimal or percent) are variables that can be manipulated. The circuit architecture employed utilizes a central processor unit, read only memory, random access memory, keyboard, and display. A fractional computation unit is a unique contribution. The keyboard contains numerous keys devoted to direct fractional keystroking. The scaling capabilities are also a unique contribution.