Gracyn's lesson covered the concept of double plus 1 and doubles minus 1. We discussed how doubles facts can be used to solve problems when one of the addends is increased by one or decreased by one. Gracyn completed doubles fact problems, using cubes as models, then determined if she used doubles plus one or doubles minus one. Together, we played a game of Tic-Tac-Doubles. We took turns solving problems that were circled if they were a doubles fact. The problems were X'ed if they were a doubles plus or minus one fact. To finish, Gracyn worked on a Sudoku puzzle.