Welcome back to the fort, where today, we’re going to solve some problems!

If you were with us last time, you’ll remember that we were learning to think like engineers. Engineers are people who make something to solve a problem.

And the thing that they make to solve the problem is called a solution. Squeaks and I were looking for a solution to the problem I had...and still have it! My back is really itchy!

And the itch is in a place that I can’t reach! Since we were thinking like engineers, Squeaks and I decided to follow the same set of steps that engineers use to solve problems! Do you remember the steps?

You're right, Squeaks! The first step is Ask. We asked—and answered—questions about the problem, like “what is the problem?” and “what can we use to solve it?” Then we went looking around the fort to find stuff we could use to build our solution.

And here’s what we found: some rulers, modeling dough, pencil, a plastic fork, the cardboard roll from a roll of paper towels, and some tape. Now, we don’t have to use all of this stuff. But we can only choose from what’s there.

All right! The second step is...right again, Squeaks! Imagine.

We used our imaginations to think of solutions to the problem of my itchy back...and decided to build back scratchers. Then, we decided to take some time to draw some ideas for back scratchers using a pencil and paper. I think I’m done with mine, Squeaks.

Are you? Great, because this itch is really annoying! Do you remember the next step that engineers take?

You’re on a roll, Squeaks! You are right! The next step that engineers take to solve problems is to create.

That means it’s time to build our back scratchers! We’ll look at our drawings and do the best that we can to make what we’ve drawn... And we’re done!

After engineers have made their solution…or at least a model of it…the next step is to test it. In engineering, “testing” means trying out an idea to see if it solves the problem. Let’s try my back scratcher first.

I used some tape to fasten the plastic fork to this pencil. Alright, here it goes! The back scratcher doesn’t quite reach the itchy spot on my back.

It’s just too short. So my idea doesn’t do a good job of solving the problem. And that’s okay.

Not all ideas work! If an engineer’s idea doesn’t work…they pick another one to test. Engineers don’t give up, and neither do we.

So, let’s test Squeaks’ idea! His design uses modeling dough to stick the fork on the end of a ruler. So let me give it a try!

Well, it’s definitely long enough to reach my itchy spot Uh oh Oops…looks like I pushed a little too hard, though. The fork fell off of the end of the ruler. I guess the dough wasn’t strong enough to make it stick to the ruler But that’s okay...because we have one more step to take!

That's right, Squeaks…improve. Improve means to make better. What engineers do…and what we need to do…is to look at our idea to see if we can make it better.

While the second back scratcher worked…it did fall apart. So let’s see if we can improve it, so that it doesn’t fall apart. Hmm.

My back scratcher wasn’t long enough but it did stay together. I used tape to hold the fork on to the pencil, and Squeaks used modeling dough. I wonder what would happen if we used tape to hold the parts of Squeaks’ back scratcher together, instead of the dough?

Let’s try it and see if this improves our second idea. Okay, we did it! Now let’s test it again.

And…it works! It is long enough to reach the spot on my back…and it stays together. Using the tape instead of the modeling dough improved our solution!

Now, if we wanted to, we could try to build a totally different solution with the same stuff, to see if we could come up with an even better back scratcher. We could try using the paper towel tube to make it longer...or see if there was a way to make one that folds up so that I can keep it in my pocket. There’s no limit to the number of solutions we could try!

But for now... I’m just glad to not have an itchy back anymore! Thanks for joining me on SciShow Kids and a big thanks to Google Making Science for helping us make this episode!

Do you have an invention you’d like to show off? We’d love to see it! Ask a grownup to help you leave a comment on this video, or to send an email to kids@scischow.com!