This is a funny little article. University of Chicago researchers found teachers were most effective at teaching math if they presented their language in a bit of a jumble. They verbally taught one way, but gestured to explain the visual processes at the same time. This mish-mosh was dramatically more effective in helping kids learn than if the teacher tried to explain both methods verbally. With that approach, the kids were overwhelmed.
We think this is because the dominant visual learning kids are just watching (they're not listening), and the dominant auditory kids are just listening (and not watching). This harkens back to that finding that 9-10 year olds can't take in more than 13-word sentences at one time (Everybody's Talking..).
Studies like these are cautionary to teachers - "Beware of TMI" or Too Much Information.
Teaching Math Two Ways Best for Learning