(all you could really do was +, −, ×, ÷, square roots, and percentages). Note the very basic 8-digit green display (it's called a vacuum fluorescent display) and the relatively small number of mathematical functions Photo: This is what calculators looked like in the 1970s. Thanks to the development of silicon microchips in the late 1960s and The first affordable, pocket, electronic calculators started to appear, Widespread use from the late-19th to the late-20th century. Mechanical calculators (ones made from gears and levers) were in Photo courtesy of National Institute of Standards and Technology Digital Collections, Gaithersburg, MD 20899. Read the result in the little "windows" at the bottom. You enter the numbers you want to work with using the nine columns of octagonal keys at the top, crank the handle, and Photo: A Burroughs Mechanical calculator from the early-20th century. Indeed, the word calculator comes from the LatinĬalculare, which means to count up using stones. People have been using aids to help them calculate since ancient Minus two") before our brains start to ache and forget. Remember typically 5–9 digits (or, as Miller put it: "the magical According toĪ famous bit of 1950s research by psychologist George Miller, we can In our heads because they can store only so many numbers. Our brains are amazingly versatile, but we find it hard to calculate The machine along with a small button battery. The lighter gray keys above them carry out a whole range of scientificĬalculations with a single button click. Larger dark gray keys at the bottom are the numbers and the main "operators" (+, −, Larger "natural display" that can show entire equations and even perform calculus! The Photo: My newer Casio Calculator, an fx-991ES, has a much How does a calculator add two numbers together?.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |