Interesting Math History

Question :
How did the word 'Calculate' originate ?

Answer :
When people first began to count, little by little they found out how to add, subtract, multiply and divide. And in some countries special devices were invented to make computation easier, especially in dealing with large numbers.
The Romans used a counting frame, which is today known as Abacus, in which units, fives, ten and so on were represented by heads, which could be moved in grooves.
These heads were called Calculi which is plural for Calculus or pebble. Since Calc means lime and marble is a knid of lime-stone, it is clear the heads were of marble. This is the origin of the word Calculate.