Modern electronic calculators are handheld electronic machines capable of performing mathematical operations. They have integrated circuit chips, but their structure is much simpler than computers. They can be considered as the first generation of electronic computers, and their functionality is relatively weak. However, they are convenient and inexpensive, and can be widely used in commercial transactions. In addition to displaying calculation results, they also often have overflow indication and error indication. Calculator power sources include AC converters or batteries, which can be recharged with AC converters or solar energy converters. To save energy, office calculator products use large scale integrated circuits made with CMOS technology.
In ancient times, people invented many calculating tools, such as counting rods, abacuses, and calculating rulers. With the development of society and the progress of technology, the development of calculating tools has changed from simple to complex, from low-level to high-level. After entering the 20th century, people invented calculators. The appearance of office calculators solved many relatively complex calculation problems. Calculator use is very simple. Its calculation rules are calculated from left to right. After entering data, the results can be obtained in an instant.
Office calculators generally consist of an arithmetic unit, a controller, a memory unit, a keyboard, a display, a power source, and some optional peripheral devices and electronic components, assembled manually or by machine equipment. The arithmetic unit and controller of low-end calculators are implemented with digital logic circuits for simple serial operations, and their random access memory has only one or two cells for accumulation and storage. High-end calculators use microprocessors and read-only memory to implement various complex operation programs, with more random access memory units for storing input programs and data. The keyboard is the input part of the calculator, generally using contact or sensor technology. In order to reduce the size of the calculator, one key often has multiple functions. The display is the output part of the calculator, and it may have light emitting diode displays or liquid crystal displays. The calculator has integrated circuits (see complementary metal-oxide semiconductor integrated circuits) and is equipped with an automatic power-off circuit that stops when it is not actively used. Optional peripheral devices for calculators include miniature printers, box-type magnetic tape machines, and magnetic card machines.
From a certain perspective, the broad term "computer" includes "electronic calculators". Office calculators also have integrated circuits, but their functionality is simpler and their prices are cheaper, making them more portable and stable.
In the past, devices such as abacuses, Napier's bones, mathematical table books, engineering slide rules, and mechanical adding machines played auxiliary roles in numerical calculation. The word "calculator" originally referred to professionals who performed mathematical calculations using pen and paper. This semi-manual calculation work was both heavy and error-prone.
Modern office calculators use electricity as a power source, and come in various shapes and sizes, from inexpensive and credit card-sized simple equipment to special calculators with printing functions.