I use Hairy Math to help my 1st-grade students understand the concept of missing addends. They love drawing hair on top of the missing addend box to find the answer. It could also be used with students having trouble with the concept of missing addends. I have also included some problems that review order of addends, a challenge problem and a spot for a student created problem, to extend learning. Once explained, this would make a great math center. The first page gives an explanation and would be a great cover page for the center.