This is a wonderful resource to use for any math series. It is based on the 5 and 10 system. We use Singapore Math so it is a part of our everyday routine. The children love using these. In this set are combination flash cards of 5 and then as the children progress there are combination flash cards to 10. I mixed them all together and we see how fast we can say the missing number. Copy these onto card stock , cut in half and use as flash cards. It is great for teaching number bonds. There is also a set to help the visual learner where the missing number is represented by a ten frame. The children can see visually what is missing. Also included are number bond cards where the children having a number bond and say the missing number. These are both represented in number bond to 10's and number bond to 5's. Assessment are number bond worksheets (fact family) that the children can complete to show an understanding. There are 42.00 pages included in this mini unit.