THE CREATION OF ZERO AND PI
How did the concept of zero evolveover time?
The concept of zero developed because it was necessary to have a placeholder—or a
number that holds a place—to make it easier to designate numbers in the tens, hun-
dreds, thousands, etc. For example, the number 4,000 implies that the three places to
the right of the 4 are “empty”—with only the thousandths column containing any
value. Because zero technically means nothing, at first few people accepted the con-
cept of “nothing” between numbers. Not that all cultures ignored the possibility of
such an idea. For example, Hindu mathematicians, who wrote their math in verse,
used words similar to “nothing,” such as sunya(“void”) and akasa(“space”). It is
thought that the Babylonians were the first to have a placeholder in their numbering
system, but not a zero; instead, it appears they used other symbols, such as a double
hash-mark (also called wedges) as a placeholder.
Archeologists believe a crude symbol for zero probably started in Indochina or
India about the 7th century—and by the Mayans independently about a hundred years
earlier. While the isolated Mayans could not spread the idea of the zero, the Indians
seemed to have no problem. Around 650 CE, zero became a mathematically important
number in Indian mathematics—although the symbol was a bit different than today’s
zero. The familiar Hindu-Arabic symbol for zero—the open circle—would take several
more centuries to become more readily accepted. (For more about zero and Hindu-
Arabic symbols, see “History of Mathematics” and “Math Basics.”)
What is piand why is it important?
Pi (pronounced “pie”; the symbol is π) is the ratio of the circumference to the diame-
ter of a circle. Another way of looking at pi is by the area of a circle: pi times the 37
MATHEMATICS
THROUGHOUT
HISTORY