In our daily life we might face some situations that force us to make some mathematical calculations so we resort to a calculator whether of the cell phones or the computer for doing so .have you ever imagined how they were doing this before inventing the calculator

Can you imagine the problems that could face those who work in the field of
mathematical equations and the sum of the obstacles that was facing them without calculators and how scientists like ISSAN NEOTEN ,JOHANS KELLER and LORD KLEN could help the humanity with their inventions

These equations may seem brilliant these days but have you ever thought of the effort that was exerted to do some calculations before inventing the calculator

The world didn`t know such invention before 1960 till the time of BLAISE PASCAL the inventor of the first mechanic calculator (not electronic) also the PRINCIPALITY OF LIECHTENSTEIN was famous with mechanic watches industry in 1947 but it was giant ones not like those we use now a days

In spite of all the obstacles in this time,  there were brilliant minds like Blaise Pascal,  who invented the first mechanic calculator after him Curt Herzstark completed the design while he was in the jail to be manufactured and launched into the markets in 1948

We know that a picture worth a thousand words so let`s see these photos

Also we have a video explains how it works

sources: 1,2,3