will: deanna smith is still full of third graders focused. >> and what did they do on their snow day? will: right now, she says the key is to keep her students moving. >> we have so much curriculum we have to cover, so we don't get a lot of time to do that. so anytiti i can find ways to make them move, and not disturb the classroom, that is a benefit for us. will: smith asked the school's art teacher to help her come up with a way to keep students alert and active, even when they haveveo stay seated. >> okay, who's dropping the bucket? it's down here. >> and she jokes that she can see it, but she doesn't know how to make it. but i can see what's in her brain. i make it. will: the two initially thought about getting a desk with a treadmill attached, but the cost would be way too pricey. a better idea came along, though, when someone sent the two friends this video on facebook. >> and it's just rows and rows of children, just gently, quietly swinging their feet. and it just [snap] i saw it in my brain. i saw how to build it. will: the product they built can desks. they're swinging footr