Telephone mounted calculator

A calculator adapted to be used with a push button telephone having an array of telephone push buttons, said calculator comprising:

• a cup-shaped housing having an opened mouth adapted to fit over the array of push buttons of the telephone and to be secured in place thereover, said housing having a plate, said plate including an array of apertures extending therethrough, said plate having inner and outer faces;
• a first array of finger discs corresponding to at least some of the telephone push buttons for actuating them and bearing indicia on the front faces of said discs, said discs normally at least partially extending outwardly from the outer face of said plate, said discs having rear faces on the opposite side of said front faces;
• a series of elongated legs fixedly connected to said rear faces and slidably extending through said apertures to the telephone push buttons for actuating them selectively when depressed and alternatively maintaining said discs normally at least partially extending outwardly from the outer face of said plate, at least one of said legs having an axially-extending front portion disposed in axial alignment with its aperture in said plate and having a laterally extending intermediate portion connected at its forward end to said front portion and terminating in a foot portion adapted to engage one of the telephone push buttons;
• logic circuit means mounted within said housing for performing mathematical calculations;
• display means mounted on said housing and responsive to said logic circuit means for indicating information concerning said calculations;
• first switching means mounted on said housing and responsive to said finger discs for causing the generation of input information for said logic circuit means;
• a second array of finger discs bearing calculating indicia on the front faces thereof;
• and
• second switching means mounted on said housing and responsive to said second array of finger discs for causing additional input information to be generated for said logic circuit means.