The number of keys on a keyboard are reduced by employing the decimal point key as a control key when stroked the second time in the entry of a decimal number word. This eliminates the need for a key standard in the computer arts which is either designated as an "enter" key or as an "=" key depending upon the computer arithmetic process. It thereby becomes possible to use only twelve keys on a keyboard to control a modern computer with the order of 133 built-in programs or execution commands. This is done by providing in addition to ten decimal keys 0 to 9 and the decimal point key one additional control or execute key which initiates a two or more sequential key program step select mode in which any of the twelve keys are then stroked to designate a particular execution command. An accompanying graphic display of the various execution choices available makes the keyboard usable without necessity of frequent consultation of an instruction manual.