A calculator is a device that performs mathematical problems enabling the user to find answers to complex problems faster than ever. Plus with technology improvements, calculators are now able to fit in the palm of your hands. Also calculators are able to do a lot more complicated problems today, and display them on much larger screens (example: graphic calculator) .
One of the early calculating tools were called "The Abacus". It was a simple instrument for working on math problems. It was used by many cultures and dates back to ancient times. Another early calculating tool was called the "Slide Rule". An English man called William Oughtred invented it in the early 1600's. The slide rule made multiplication and division much easier. Engineers and scientists used the slide rules until the invention of calculator in the early 1970's.
Until the late 1960's, hundreds of different types of calculating machines were also invented; they all used different types technologies. One of the most popular was the stepped-drum and pinwheel mechanism. These early calculators were large, very heavy, and expensive. The early ones needed the user to pull a hand lever to turn the calculating mechanism. Later on they used electrical motors to turn the mechanism. Compared to calculators we have in our pockets today, these calculators are almost useless to us. The early ones could do the four basic operations: addition, subtraction, multiplication, and division.
The calculators that we all use today can do a lot more complex problems, plus some of them allow the person using it to store numbers in the memory. Some have the ability to do complicated geometric, algebraic, trigonometric, statistical, and calculus functions. Now calculators operate on electrical power either by batteries, or solar cells. Also man is now able to read the answers on digital displays, most of them now use some form of LCD screen.
