how did the babylonian economy work without system currency?

Answer 1

Babylonia had an exchange medium, it just wasn't coinage. The use of precious metals with a defined weight predated coinage. In the ancient Middle East a weight called a shekel was used.

There are more details than you probably want to know, but I've cut and pasted some of them here to highlight relevant portions of the website entry I took them from.

From "part of the book ANCIENT WISDOM AND FOLLY" by Sanderson Beck (1)

"Babylon was the busiest center of trade at this time connecting Egypt, Phoenicia, and Syria to Cyprus, Asia Minor, and Elam. Weighed silver was the primary currency, as there were no minted coins. In the sixth century BC while most people were suffering hardship, powerful capitalists arose, particularly the Egibi family in Babylon, with fortunes in real estate, slaves, money-lending, commerce, agriculture, and banking. These inequities were probably factors in Babylon's loss of political autonomy."

Here is an excerpt from the Jewish Encyclopedia website (2):
"For money, as for weight, the shekel was the standard unit, the pieces of metal being either fractions or multiples of the shekel. The struggle between the Egyptian decimal system and the sexagesimal method of the Babylonians first made itself felt in regard to weights of gold and silver. The Phenicians were probably the mediators; and a mina of 50 shekels was established as a standard. According to certain indications, the relative value of gold to silver was as 10 to 1. Later, in consequence of the great increase in the supply of silver, the relative value was as 40 to 3. This may, perhaps, have affected the possibility of introducing the sexagesimal system.

"The gold shekel originally weighed 1/60 of a mina. The silver shekel, to have had an equal value, must have weighed 40/3 x 1/60 = 2/9 of a mina. As this would have been impracticable for use, it was decided to make a smaller piece, one more suitable for circulation. Two methods presented themselves: (1) either the silver equivalent of the gold shekel could be divided into ten parts in which case a silver shekel of 2/90 = 1/45 of a shekel of weight would result; or (2) the silver equivalent could be divided into fifteen parts, in which case a silver shekel would weigh 2/135 of a mina.

"The Mina.
"When the decimal system made its way into use, the gold mina as well as the silver mina was reckoned at 50 such shekels. Consequently there was (1) the Babylonian silver mina, equivalent to 50/45 = 10/9 of a mina of weight; (2) the Phenician silver mina, equivalent to 100/135 = 20/27 of a mina of weight.

"In the earlier system of Babylonian silver values (which was used also in the Lydian and Persian kingdoms) the silver shekel was divided into thirds, sixths, and twelfths, whereas in the Phenician system it was divided into halves, fourths, eighths, etc."

Answer 2

http://ca.wrs.yahoo.com/_ylt=A0geunHHfCJFbBkA60TrFAx.;_ylu=X3oDMTB2b2gzdDdtBGNvbG8DZQRsA1dTMQRwb3MDMQRzZWMDc3IEdnRpZAM-/SIG=11uggq0lg/EXP=1159974471/**http%3a//en.wikipedia.org/wiki/Julius_Caesar