Most primary reading and writing schools are located in churches and monasteries, and some priests teach in their own homes. Children usually start learning at the age of 7, and teachers adopt the method of individual teaching, mainly orthodox teaching and training children. In order to prevent the influence of heresy, the children's behavior is strictly supervised. Both schools and families impose severe corporal punishment on children. Textbooks in schools are all manuscripts, and it was not until the second half of17th century that printed textbooks were widely used.