Calculator watch Calculator watch A calculator watch is a digital watch with a built in calculator, usually including buttons on the watch face. Calculator watches were first introduced in the 1970s and continue to be produced, despite falling from their peak popularity during the 1980s. The most notable brand is the Casio Databank series, though watches made by Timex were also popular. Most calculator watches contain only a few number of functions such as +, -, x, / and percents. However, there are several models with additional functions: scientific, including transcendent and trigonometry, in models Casio CFX-200, CFX-400, Citizen 49-9421, and also
Sumlock ANITA calculator "no binary stunts here!". Similar to the Comptometer calculating machines of the time, the ANITA had a full keyboard, a feature that was unique to it and the later Sharp CS-10A among electronic calculators. Being silent and very quick in operation, and the only electronic desktop calculator available, the ANITA sold well, reaching nearly 10,000 units per year by 1964. 1961 was a doubly notable year for the Bell Punch Company since it then also amalgamated its calculator division with the British operation of Comptometer Corporation of Chicago, U.S.A. (formerly the Felt & Tarrant Manufacturing Co.), to form Sumlock Comptometer