How many Mongols lived during times of Chinggis Khan?

Mongols used a decimal system to organize themselves.

The nucleus of a nomadic system was one family. One ger-one family. Each family had to produce one solider. Ten families would form one unit, aravt. Ten aravts would be zuut, one hundred. Ten zuuts would be myangat. Myangat, or one thousand soldier was the main unit organized under a noble. So a noble would have a…