Frishauf, Holtz, Goodman & Woodward
Calculator with equation display device
 A calculator in which when numerical information and function information are sequentially input using ten keys and function keys of a key input section for obtaining a calculation result according to a calculation formula, the input information is stored in a memory. The operation is then performed and, simultaneously, a character formula universally representing the calculation formula with the input numerals replaced with characters is prepared. This character formula is displayed by the display section so that the input condition may be easily confirmed and input errors may be prevented with certainty. 
Casio Computer Company, Ltd.
G
G06F
inventional
Hisashi
Ito