[ja27]

But the students aren't supposed to know that yet. That's literally two topics later in the Common Core Standard, so they won't learn that for another day or two. Smh.

http://www.corestandards.org/Math/Content/3/OA/

[Mindless2112]

Punishing students who are ahead is an excellent way to make all students equally disinterested. (Oh, but not equivalently disinterested.)

The question is whether the student knows about commutativity of multiplication or if he/she didn't understand what was taught or made a mistake.

Personally, I think the problem here is that math is taught as processes rather than as concepts.