Notes: "Here we have three slide adders: an Addiator Duplex, a Midget Adding Machine, and a VE-PO-AD (Vest Pocket Adder). The Addiator was very clearly built to be used as a real adding machine, albeit an inexpensive one. The Midget and VE-PO-AD on the other hand, well, they have the look, and more importantly, the feel of novelties, rather than something to be taken seriously. "
