Teaching is one of ability that does not possessed by all people. There a many things that should be considered in teaching. We should have not only understanding the lesson, but also skill in teaching. Teaching is an action where we transfer our knowledge to other people. In teaching, there are many ways to do that. If we want to teach something, there is a factor that should be considered. That factor is age. If we want to transfer something to other, we must know for whom that knowledge to be shared. By knowing the ages, we can understand how, when, and what lesson that could be taught.