BOY: Lots of kids each year are getting seriously injured by falling back in their chairs.

We don't want that to happen.

This causes thousands of head injuries each year with in-school age children.

We've come up with a potential solution to fix this problem.

There was only one study on kids falling back in their chairs, and it was approximately 5,000 kids in Britain.

So then we took the kids in Britain who were injured by falling back in chairs.

We calculated how many students in school are in Britain.

We ratioed that out, and then we applied the ratio to the students in Canada, and that's where we got 5,032 serious head injuries in Canada each year.

- We figured the best approach would be to attach something near the rear feet of the chair that acted like a brace or a platform that would prevent the chair from tipping backwards.

We were trying to think of cheap materials to buy and also easy materials to find, so we decided on wood, because it's fairly cheap, it's easy to find, and also it's easy to make something out of it.

- We started with drawings.

We scaled everything out and then headed over to my garage and we just cut the wood, we applied the huge hole, and then just little finishing touches.

- In total, it took about half an hour to make the first prototype.

When we tested the first prototype at my house, we put it into the skinny-leg chair.

The prototype worked, but when we brought it to school the next day we realized that it doesn't fit on the school chairs and that we had to make a new prototype.

Houston, we got a problem.

- What is it?

- It's not big enough.

- Yeah, and also I just noticed, this is a straight hole and that's an angled chair.

- Yeah, so it wouldn't have worked.

- Yeah, we need to change that.

- We need to change it, we need to put it on an angle.

- The chairs around my kitchen table are straight, like at a 90-degree angle to the floor.

- But the school chairs are angled outwards and meet the floor at a 60-degree angle.

- So we needed to change the angle of the hole we drilled into the wood.

- We also needed to make it bigger, since the school chair legs were thicker.

- We never even thought to measure the first time.

- We brought it to school and then we... when we got time to test it out, we did.

- So the low-friction slider is designed to reduce friction between the floor and this device, which doesn't allow the kid to fall back on their chair.

Next, the felt slider is designed to reduce noise in the classroom and not damage the floors at the same time.

- We added the screw to help it not fall off the back of the chair.

- All right, let's try it.

- Who's doing it?

- Vagelli.

- All right.

- It works!

(applause) Come on, come on!

- It feels really good to know that kids can be safe with our invention and that it was really fun to work with the team as well.

I'm pretty proud of our whole group.

We worked really well.

- It was a long process, but definitely was worth it.