Abstract: A data processing apparatus includes a novel method of entering the data for a function which requires two integral operands. First and second preselected sets of the digits of the current output numerical value are interpreted as the first and second integral operands. In the preferred embodiment a predetermined number of the least significant whole number digits is interpreted as the first operand and the predetermined number of the most significant fractional digits is the second operand. This data entry method reduces the amount of memory required to store the operands and to execute the function. This data entry method also enables entry and execution of these two variable functions in the same mathematical hierarchy as single operand functions. In the case of the preferred embodiment, in which this data entry method is used for calculating permutations and combinations, this is the preferred and mathematically correct method of executing these functions.

Abstract: A data processing apparatus having a plurality of preprogrammed functional operations and at least one user accessible memory includes a generalized input sequence for combining functional operations with data storage in one of the user accessible memories. In the case where a number of user accessible memories is provided, memory entry is enabled by a store input followed by an input designating the memory while a memory recall operation is enabled by a recall input followed by a memory designation input. The algebraic memory operation and entry sequence requires entry of the store input, the desired operation input and the memory designation input. If a unary operation is selected, the selected operation is performed on the data stored in the output indicator memory or alternately on the data stored in the designated memory and the result is stored in the designated memory.