My students love these number puzzles. They are a great way to practice different strategies for adding and subtracting two-digit and three-digit numbers. They help students play with decomposing numbers to build addition and subtraction math strategies
'Marvin the addition monster' Pick a card (visual reps on cards) and put corresponding number ring on Marvin's horn. Put correct amount of blue counters down one horn, and yellow down the other. Open Marvin's mouth and you've got the total.