Jehan Adam

Who is Jehan Adam?

Jehan Adam was a French mathematician who flourished in the 15th century. He was secretary to Nicholle Tilhart, who was notary, secretary and auditor of accounts to King Louis XI of France.

He published a manuscript in 1475 containing the first use of the terms bymillion and trimillion, which gave rise to the modern terms billion and trillion. His usage referred to the long scale values of 10¹² and 10¹⁸ respectively. These terms have subsequently been revalued in English to the short scale values 10⁹ and 10¹² respectively, although the original values remain in long scale countries.

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