Towers of Ten

During math today students worked with a partner to build three towers of ten cubes, and then wrote equations for each one.  We ended our session by sharing the combinations of tens that were found, and then took it farther to see if we could decipher if we had found all of the possible combinations for ten.  During this discussion first graders made a big discovery: after finding one combination that equals ten, they could then "flip flop" the two addends to make another true equation!