|Taken from the CA 2nd grade math framework.|
Now I have a handful of students decomposing numbers in ways that aren't really "helpful." For example, last week a student was working on the problem 9+7. He broke up the 9 into 5+4, then he added the 5+4 to make 9, so now he had 9+7 again, which he said is equal to 16.
I have watched a few students do this. I observe that they understand that they can break a number up into parts and those parts are equal to the number it was decomposed from, but maybe they don't see decomposing as a STRATEGY to use. I watched a handful of students do this last week over and over again. I'm wondering... Did I say or do something to encourage this strategy which created an "answer getting" type of feel or are they trying to copy someone in class without really understanding the purpose? I'm wondering, what do I do here? I would worry that a talk about efficiency during a Number Talk would be ill timed and work against the positive disposition toward math that I am trying to cultivate. Part of me thinks to leave it alone and let students work it out in their own time. The other part of me wonders if I could tackle this outside of Number Talks during a math lesson or during our procedural fluency/math intervention time. I would love to hear your thoughts. Thanks in advance!