Definition of: numeration

(n′·mə·rā′shepn, ny′-) noun
1. The act or art of reading or naming numbers, or a system of reading or naming them, especially those written decimally and according to the Arabic notation. Compare NOTATION. For numbers above and including 1,000,000,000 there are two systems in use: the French, used commonly in the United States, and the English. In the former, the above number is read one billion; in the latter, one thousand million. In general, in the former the successive names billion, trillion, etc., apply to the results obtained by multiplying 1,000 twice, thrice, etc., by itself; in the latter to those obtained by multiplying 1,000 by itself four times, six times, etc.
2. Enumeration.