Ancient bookkeepers used small clay balls called tokens to count and keep track of existing wealth. Different shapes represented different items: circles and spheres could represent sheep and grain.

An important landowner had a complete Envelope and tokens used in the Fertile Cresent inventory--before writing, money, or the abstract concept of numbers. As civilization became more complicated, the token system expanded to allow more detailed and more abstract accounting.
Tokens seem to have been used as evidence of transactions. Simple tokens could be found in clay "envelopes" from about 4000 BC in Sumeria. The tokens were hidden from view, but scribes impressed each token on the outside of the envelope (the first seal impressions). The envelope may have been a summary document, with the tokens inside representing an inventory--possibly a "balance sheet" with a complete listing and equivalent tribute or debt payment associated with a personal account or a specific trade or tax transaction.