Placing emphasis on understanding can help children remember ideas long-term. Ask the children to explain why they have done something and what they think about the process. It is better for a child to follow a structured procedure and arrive at an incorrect answer than to fumble to a correct answer. Praising young students for the correct thought process and way of thinking will encourage this. Linking branches of mathematics together, such as division and multiplication, helps the students form their own patterns of understanding.
Visual aids can help clarify the explanation of mathematical concepts. Young children are only just creating the mental idea of what a number represents. By using tools such as abacuses, scales, games and other hands-on visual aids, students can build up mental representation of what these numbers actually mean and the various methods in which they can be applied. Three divided by two would confuse most young children, but they should understand the concept of one and a half pieces of cake each.
Another teaching strategy that works well with young children is reinforcing a new concept with additional problems. Once a topic has been covered, give students a related problem they have not seen before. If they can apply the previous knowledge to solve the new problem, you can be sure the material is well understood. If not, use other examples to reinforce the idea (musical, written, vocal or spatial). Briefly recapping the material one or two days later also helps consolidate the topic.
Relating the material taught to how it applies to the real world should keep the classes interesting and stimulating. Most children are not passionate about pure mathematics, but when explained in the context of some real-world application -- for example, construction, money or fashion -- most children become engaged. If you can take away the stigma attached with mathematics, it can be taught effectively and children can have fun and learn without even realizing it.