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the human body’s ten fingers and toes apparently caused man to construct tools to help him
with calculations.

Abacus

• Abacus was the first mechanical device developed in China.
It was used for calculations.
• It is made up of a wooden frame with rods, each having a
certain number of beads.

• The frame is divided into two parts-Heaven and Earth.
• Each rod in Heaven has two beads and each rod in Earth has
five beads.

• It is used for addition, subtraction, multiplication, and
division. Abacus

Napier’s bones

The Napier's bones, also called Napier’s rods , was invented
by the Scottish mathematician John Napier in 1617. It
consists of nine bones or sticks with numbers marked on
them. It was used for addition, subtraction, multiplication,

division and to find the square root of a number.
Napier’s bones
ELECTROMECHANICAL COUNTING DEVICES

Pascal’s Adding Machine
• In 1642, Blaise Pascal, a French mathematician, invented the
adding machine called Pascaline or Pascal’s Calculator .
• It used gears, wheels, and dials.

• Numbers were displayed by rotating the wheels. Pascal’s Calculator
• It was capable of performing addition and subtraction. The gear principle was further
employed in many mechanical calculators.

• A Taximeter is a perfect example of a mechanical calculator.
Leibniz Calculator

• In 1673, Leibniz, the famous German mathematician,
invented a mechanical device, called the Leibniz calculator .

• It was an improvisation on Pascal’s machine.
• Apart from performing addition and subtraction, the Leibniz
calculator could even do multiplication, division, and find
square roots.
Leibniz Calculator
Difference Engine and Analytical Engine

• Charles Babbage, a British mathematician is considered as the Father of computers.

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