<Table> <Tr> <Td> </Td> <Td> This article is written like a personal reflection, personal essay, or argumentative essay that states a Wikipedia editor's personal feelings or presents an original argument about a topic . Please help improve it by rewriting it in an encyclopedic style . (March 2010) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article is written like a personal reflection, personal essay, or argumentative essay that states a Wikipedia editor's personal feelings or presents an original argument about a topic . Please help improve it by rewriting it in an encyclopedic style . (March 2010) (Learn how and when to remove this template message) </Td> </Tr> <P> 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 . </P> <P> Most calculator watch contains only few amount of functions like +, -, x, / and percents . Howewer, there are several models with additionas functions: scientific, including transcendent and trigonometry, in models Casio CFX - 200, CFX - 400, Citizen 49 - 9421, and also financial functions (in the Casio CBA - 10). </P>

When did the casio calculator watch come out