Abstract: The present invention is a low cost electronic apparatus construction method which may be employed for hand held calculators, electronic learning aids and electronic games. This technique involves a simplification in the construction of the apparatus including reduction in the number of piece parts necessary for the assembly. The primary electrical circuit interconnection pattern of the electronic apparatus is printed upon a part of the case of the apparatus which must be nonconducting. This printed circuit pattern together with the construction of the back case includes connection portions for electrical connection to the major components of the apparatus which may include an integrated circuit, a display device and an electrical power source. The primary circuit pattern printed on the back case includes a plurality of interleaved comb key switch positions.