käsilaskimet

Käsilaskimet are compact, portable electronic devices used for arithmetic calculations. They are typically powered by batteries or solar cells and display results on an LCD screen. They come in a range of models, from basic four-function devices to scientific, financial, and graphing calculators, with features such as memory registers, square root, percentage, and exponential functions.

The development of handheld calculators began in the late 1960s and early 1970s, with rapid commercialization by Japanese firms such as Sharp and Canon, followed by others including Hewlett-Packard. Advances in low-power integrated circuits and liquid crystal displays made pocket-sized devices practical. The HP-35, released in 1972, popularized handheld scientific calculation. By the mid-1970s prices fell and consumer adoption increased. Solar-powered versions appeared alongside battery-powered ones, broadening availability.

Types of käsilaskimet range from basic four-function models used for everyday tasks to scientific calculators that provide trigonometric, logarithmic, and statistical functions for education and engineering. Financial calculators include tools for interest calculations, cash flow, and amortization. Graphing calculators enable on-screen plots and more complex data analysis, and many models used in schools and universities support programming and data transfer to computers or other devices.

Impact and current status: käsilaskimet helped replace slide rules and facilitated quick, reliable computation in offices, classrooms, and fieldwork. In recent years, smartphones and calculator apps have largely supplanted dedicated devices for casual use, but dedicated handheld calculators remain common in education, certain professional contexts, and specialized applications where reliable numeric computation is essential.