The Sumador Chino On a recent motor trip through Mexico, the writer came across on adding device which was referred to as a sumador chino (Chinese adder). A survey of the more available literature on the history of mathematics and on instruments of calculation has uncovered no reference to such a device. The purpose of this communication is to enlist the help of other members in bringing to light whatever may be known concerning the evolution and present status of the sumador chino. CACM November, 1960 Rogers, J. L. CA601119 JB March 20, 1978 6:50 PM 116 5 116 116 5 116 116 5 116