CALCULATOR:  The simplest form of calculating machine is the wooden counting frame, or abacus, with moving beads strung on wires which represent units, tens, hundreds and so on. This device has been used in China for thousands of years – it is so ancient that its exact time and place of invention are unknown.

The forerunner of the modern day calculator was the slide rule, invented in 1622 by William Oughtred,an English mathematician. He said he used the newly invented Logarithms to make a device that would simplify multiplication and division. Two scales were held together and slid along each other. Later rules consisted of a slider moving in a frame.

Blaise Pascal Adding Machine
Blaise Pascal Adding Machine

The French mathematician and religious philosopher, Blaise Pascal, was 19 when he made what was probably the world’s first adding machine in 1642. It used a train of cogwheels as counters.

COMPUTER:   In the 19th century the need for rapid calculation expanded through the industrial world. Governments taxed and policed larger populations than ever before. Commerce expanded so that there were more money transactions than ever before.

Armies of clerks were employed to calculate and record the mass of transactions conducted by business house, banks and insurance companies. Scientists and engineers required even more extensive table of figures. To meet the demand, new designs of calculating machine were devised.

Charles Babbage Computer
Charles Babbage Computer

In 1834 Charles Babbage, who had invented an advanced calculator 20 years before, hit on the idea of the computer in the modern sense of the word. Calculators had a fixed repertory of “skills”; the simplest could only add and subtract, while others could also multiply and divide. A computer, as conceived by Babbage, went far beyond this. It was a general-purpose calculating machine capable of carrying out any calculation that the operator could specify. It could even “decide” how to proceed in the course of a calculation.

Babbage’s dreams of a mechanism comprising scores of thousands of gearwheels went far beyond the abilities of Victorian engineering, and the machine was never completed. But more conventional calculating machines capable of adding and subtracting and sometimes of multiplying and dividing, made progress, mainly in America. They acquired keyboards and built-in printing machines.


In the 20th century electricity was harnessed to drive a variety of calculating machines. But the first general-purpose computing machine that was fully electronic was ENIAC, completed at the University of Pennsylvania in 1945. It employed more than 18,000 thermionic valves, weighed 30 tons and occupied 1,500 sq.ft. of floor space.  ENIAC, an acronym for Electronic Numerical Integrator And Computer is considered to be the first operational electronic digital computer in the United States, developed by Army Ordnance to compute World War II ballistic firing tables.

In the post-war years more computers were built, generally in university research departments. The term “electronic brain” was coined. Nowadays computers are everywhere – even in inexpensive children’s toys.

First Electronic Calculator

POCKET CALCULATOR:   An American company, Texas Instruments, succeeded in 1971 in packing the electronic circuitry needed for a calculator on to a single Silicon Chip. Within months pocket calculators able to add, subtract, multiply and divide were being mass produced. The abilities of some modern calculators now approach those of the computer.


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