I’m not an educator by profession but I’ve done a lot of training and mentoring.
There is no replacement for actually doing the work. People who study something but don’t go through the exercises feel they understand topics better than they do. It’s only when they are put in a position where they have to apply it that the cracks in their understanding are revealed.
This would 100% result in students who thought they could explain multiplication but only had a surface level idea. The knowledge would also be fleeting because actually doing the thing makes the knowledge stick more than just observing and understanding the thing.
So yes, you still need to have the students do the thing.
Replace math with writing and it will be more obvious. It’s easy to look at someone’s writing and critique it. It’s much harder to write well without practicing.