Cool Website for teaching combinations of 10

The numbers 5 and 10 are often called the "nice" numbers. Any number you can mention is only 2 away from a 5 or a 10. This is why it is so important to be able to structure or take them apart in all the different combinations. Doing this will build "number sense" so that the children will not need to memorize or use their fingers to work problems. We encourage them to use mental math but first they must learn how to compose and decompose all the numbers. Playing the games Number Twins, Math Lines, and Numberz will reinforce the combinations of 10 and 5.