Calculator

1.

2.

Ancient Computing Tools
Abacus
Stones
Fingers

3.

Ancient Computing Tools
Suan-pan

4.

Ancient Computing Tools
The difference from
the Chinese suan-pan
is that the ropes were
arranged horizontally,
and the decimal
system was used
Board bill

5.

The first mechanical device
Wilhelm Schickard,
a German
mathematician and
astronomer, in 1623
was able to realize
his dream and
became the author of
a device based on a
clock mechanism.
The counting clock
could perform simple
mathematical
operations. But since
the device was
complex and large, it
was not widely used.

6.

The first mechanical device
Johannes Keppler became the
first user of the mechanism,
although he believed that
calculations were easier to
perform in the mind.

7.

The first mechanical device
The French physicist and philosopher Pascal,
20 years later, proposed a device that counts
using gears. To perform addition or
subtraction, it was necessary to turn the wheel
the required number of times.

8.

The first mechanical device
In 1673, the device improved by
the German mathematician
Gottfried Leibniz became the
first calculator - later the name
was fixed in history. With it, it
became possible to perform
multiplication and division.