If a child of a Russian noble didn't learn mathematics, that child was not allowed to marry. The Great Sovereign at that time, Peter I, decreed in 1699 that the New Year's celebration switch to January 1 from September 1. He also decreed that children between 10 and 15 had to learn mathematics in order to get married. This didn't apply to children of freeholders and government clerks. After children mastered math, they were given marriage certificates written in their own handwriting. If they didn't master the subject, they weren't allowed to be given these certificates, and thus, couldn't marry.
