In the third millennium , the pictorial representations became simplified and more abstract as the number of characters in use grew smaller , from about 1,000 in the Early Bronze Age to about 400 in Late Bronze Age ( Hittite cuneiform ) .
In the third millennium , the signs became simplified and more abstract . Fewer characters were used , from about 1,000 in the early Bronze Age to about 400 in late Bronze Age ( Hittite cuneiform ) .