Children may also get started with money, time, and measuring, though it is not absolutely necessary to master any of that. The teacher should keep it playful, supply measuring cups, scales, clocks, and coins to have around, and answer questions.
Long Division. There are different methods for dividing multi-digit numbers (long division). One way is a combination of estimation/ trial and error and multiplication. There is also a commonly used algorithmic method that is well explained and illustrated here at mathisfun.com.