Gesticulating helps learning

From physorg:

Kids asked to physically gesture at math problems are nearly three times more likely than non-gesturers to remember what they’ve learned. In today’s issue of the journal Cognition, a University of Rochester scientist suggests it’s possible to help children learn difficult concepts by providing gestures as an additional and potent avenue for taking in information...
It turned out to have a more dramatic effect than Cook expected. In her study, 90 percent of students who had learned algebraic concepts using gestures remembered them three weeks later. Only 33 percent of speech-only students who had learned the concept during instruction later retained the lesson. And perhaps most astonishing of all, 90 percent of students who had learned by gesture alone—no speech at all—recalled what they’d been taught.

I wonder what percent of that class were kinesthetic learners? Regardless, this seems like an easy enough learning strategy to employ into daily use. However, what would this classroom would look like during an exam, with hands flailing around among perplexed faces? :0