actually 0 was invented by hindu mathematicians before 1000 AD.
basically it has no numeral value but enormous place value.
if placed on the right side of a postive integer, the value of the number increases.
eg: 2, if placed alongside it the the value increases to 20
however if placed on the right side of a negative integer before the decimal, the value of the number decreases
eg -2, if placed alongside it the value decreases to -20
also if placed before an integer (obviously positive as decimal lies from 0 to1), the value decreases
eg 2.2 if placed before 2 after the decimal, the value decreases to 2.02
however if placed before an integer before the decimal, the value of the number remains costant
eg 2 = 0000000000000002
similarly if placed after an integer after the decimal, thenumber remains constant
eg 2.2 = 2.2000000000000000000000