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Chapter Profile
Chapter Profile
1 Early Counting Tools
Abacus—First Calculating Device
Pascaline Adding Machine
Leibniz Step Reckoner
Evolution of Charles Babbage’s Analytical Engine
Lady Ada Lovelace’s Programs
Computers Herman Hollerith’s Tabulating
Machine
Computer Generations
Dear Students! You have learnt about computers in your previous class.
Computer is a familiar word for you today. But have you ever thought ‘Who invented the
computer?’ This machine is an outcome of labour of a number of minds. No particular
person can be credited with the invention of computers, but several names stand out in the
crowd.
EARLY COUNTING TOOLS
Since ancient times, people have invented tools for calculations. Early man tied knots in a
rope and carved marks on clay in order to keep the records. They also used to count with
the help of fingers, toes, pebbles, stones, sticks, bones, etc.
Early Counting Tools
ABACUS—FIRST CALCULATING DEVICE
The first step towards computing was the invention of Abacus around 3000
years ago, in China. It is a wooden frame with beads on parallel wires which
can do simple calculations like addition and subtraction. This device is used
to calculate numbers at a fast speed.
Abacus
Evolution of Computers 7

