If you subtract 10 from 10 what do you get ?
There comes the answer "Zero".
If you take five from five you will get ......Yes again 'zero'.
Even though numbers were used by the ancient Egypts, Mayans, Arabs ,they were not sure of this zero. They wondered how could ' nothing ' be ' something '. They used the words,vacum, naught, nil, void whenever they had to use zero. Sometimes they used the letter ' N ' too.
Now comes the interesting question.
Then, how did the world come to know about 'Zero'?
It was around the 5th century that the world accepted zero. That contribution was from our(India) mathematician and astronomer 'Arya Bhatta'. He treated '0' as a number and discussed operations involving it including division.
AryaBhatta is also called as BrahmaGupta. It is said he was born in Ashmaka .This region lies betwen Narmada and Godavari .This is now identified with Maharashtra . There is also another opinion that he was born in Kerala. Wherever he may be born , he went to Kusumapura for higher studies. Bhaskara, his disciple identifies this place with Pataliputra which is now called as Patna. His higher studies were in Nalanda University in Patna. Later he also became the head of this famous university.Though he did not explicitly mention zero as a number, the French mathematician Georges Ifrah argues that the knowledge of zero was implicit in Aryabhata's place value system.
He authored many books which are lost. His major work 'Aryabhatiya ' is a blend of astronomy and mathematics. Aryabhata was able to tell us the diameter of the earth, much before Galelio did. His famous disciple was Bhaskara who was also well versed in these theories.
As a mark of honour, Government of India named its first satellite as Aryabhata and the next one as Bhaskara .