Have you had any difficulty teaching kids how to add or subtract numbers? Most kids are familiar with coins and you can capitalize on that to teach them about numbers. Kids will understand how to add & subtract numbers quite easily and logically.
In addition, using money can be a great way to introduce kids to the concept of decimals.
This e-book is a just but a start. Explore the vivid illustrations in this book for great ideas on how to excite kids to learn Math with very basic ideas that they understand. If you choose to use real coins to help them illustrate the concepts, the process can and will be much more illuminating. You will capture their attention!