1. Abacus:
The abacus was an early tool for mathematical computations. A skilled abacus user can work on addition and subtraction problems at the speed of a calculator. The abacus is still in use today.
2. Napier Bones:
John Napier invented logarithms, where the logarithm values were carved on ivory sticks which are now called Napier’s Bones.
3. Slide Rule:
Napier bones were modified by Edmund Guntur in the year 1620. It consists of a ruler and a sliding piece both marked with logarithmic values. It was further modified by William Oughtred.
4. Pascal’s calculating machine:
The first successful mechanical calculator was constructed by Pascal in 1642.
5. Leibnitz’s Machine:
It is the modified form of Pascal’s machine.
6. Charles Babbage’s Machine:
In 1833, Charles Babbage invented Charles Babbage Machine. He is known as the “Father of Computers”.
7. Census Machine:
This machine was devised by Dr. Hermann Hollerith for tabulating the 1980 US. Census.
8. Jacquard Loom:
A weaving machine invented by Joseph Marie Jacquard in the beginning of the 19th century.
