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
Comptometer The Felt & Tarrant Manufacturing Company reabsorbed the Comptograph company at the beginning of World War I The Felt & Tarrant Mfg Co became public in 1947 and changed its name to the Comptometer Corporation in 1957. In 1960, the Bell Punch Company bought the British rights to the Comptometer design and trademark, and continued its development. In 1961, Sumlock, a division of the Bell Punch Company, was renamed The Sumlock Comptometer Ltd, and began marketing the first all-electronic desktop calculator, the ANITA Mark VII. The entire calculator division of the Bell Punch Company was bought by Rockwell International in