Page 9 - Computer Class 05

Beads
Upper Deck China and other Asian countries to count and

Beam calculate, just as we use calculators.

Roads Each bead has a specific value. Reading from
right to left, the beads in the first column are
Frame
worth 1, in the second column the beads are
Lower Deck
worth 10, in the third column the beads are worth 100 etc. Addition,
subtraction, multiplication and division are performed by moving the

appropriate beads to the middle of the abacus.

Napier’s Bones

As the necessity demanded, scientists started

inventing better calculating device. In this process,
John Napier of Scotland invented a calculating

device, in the year 1617 called the Napier’s Bones .
In the device, Napier used the bone rods for the

counting purpose where some numbers are printed
on these rods. These rods can do addition,

subtraction, multiplication and division easily. Napier’s Bones
Pascaline

In 1642, a famous French mathematician Blaise Pascal , invented the Pascaline .
The Pascaline is known as the first mechanical and automatic calculator.

The Pascaline was a wooden box that could only add and subtract by means of
a series of gears and wheels. When each wheel rotated one revolution, it would

then turn the neighbouring wheel. On the top of the wheels were a series of

windows through which the totals could be read. About 50 models were
constructed and were made of wood, ivory, ebony and copper.

Pascaline

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