The ancient Egyptians were the first peoples known to have used mathematics, to calculate calendars, tides, and surveying. Each year, the Nile river would flood the land and deposit nutrients washed down from the African mountains. The flood waters would wash away the field markers, and they needed ways to figure out what land belonged to whom.
The Greeks expanded on the Egyptians' discoveries, and formalized much of what we think of as the language of math.
Source: wikianswers