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
History of science and technology in Japan desktop calculator. The Sharp QT-8D, a desktop calculator released in 1969, was the first calculator to have its logic circuitry entirely implemented with LSI ("large-scale integration") integrated circuits (ICs) based on MOS ("metal-oxide-semiconductor") technology. Upon its introduction, it was one of the smallest electronic calculators ever produced commercially. The first portable calculators appeared in Japan in 1970, and were soon marketed around the world. These included the Sanyo ICC-0081 "Mini Calculator", the Canon Pocketronic, and the Sharp QT-8B "micro Compet". In January 1971, the Sharp EL-8 was close to being a pocket calculator, weighing about one pound, with a vacuum