NTTI
Putting Together Ten
Groups explore sets of 10 items in two varieties (i.e. 3 white buttons and 7 black ones, or 5 bears and 5 bunnies). They brainstorm about their objects, write math sentences to represent what they have, and report their discoveries...
Curated OER
Let's Trade
Second graders engage in a lesson plan which focuses on adding two-digit numbers and the regrouping process. They identify when the regrouping process is necessary and make appropriate "trades" to complete an addition problem.