Answer:
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.
The Congress of Vienna was held in order for the powers of Europe to settle territories and boundaries after the fall of Napoleon's Empire in the early 1800's. The conservatives such as Austria and Prussia were quite dominant during the Congress. Their goal was to set some sort of legitimacy in the system that rules Europe, and to balance out power in the continent. France was quite vulnerable and unstable due to its background. However, instability of government was also the case for other European countries. The reason why the conservatives had their goals, is because the liberalism incited by the French Revolution has been consistent with manifesting that it has failed to keep a government's stability. Therefore, it was actually the conservatives who were successful during the Congress, as they were able to achieve their goal of keeping Europe peaceful for about a century.
