The nobles' children went to a school called a "calmecac". Its goal was to get the children ready for jobs as the Empire's leaders. These included jobs as military or government leaders; priests; scholars; teachers; and healers. These schools taught about things like astronomy, geometry, mathematics, debate, law, music, poetry, architecture, agriculture, and war. Boys had to eat and sleep at their schools. They usually started at age 15 and left around age 20 to get married. Girls could become priestesses or work in medicine, helping other women give birth.