A portable educational device that is adapted to be used in conjunction with a counter (12) having a display (14) and a keyboard (16) for input of data. A memory slot (18) or an alternate port (19) is provided on the computer (12) to receive the educational device (20). Educational device (20) contains a keypad (24) and a display (26) and operates independent of the computer (12). The educational device (20) includes a central processing unit (48), a Read Only Memory (42) and a Random Access Memory (44). A primary power source (54) supplies power to the educational device (20) during the operation thereof. A back-up power source (56) provides power to the Random Access Memory (44) to form a non-volatile memory for retention of data during periods of non-use. A connector (34) interfaces with the computer (12) to allow the computer (12) to address the Random Access Memory (44) to retrieve data stored therein and to store data at selected locations therein for use by the Central Processing Unit.