(upbeat music) - Good morning, my magnificent mathematicians.

I am so excited to be with you this morning.

We're going to have so much fun today, learning more about math and growing our brains.

It is a beautiful day outside.

Harper and I have been out here working in the yard, and we had a big idea, didn't we?

One of our favorite things out here is this beautiful flower bed, and we kind of want to have another one built.

Now, we noticed, it's made out of these picket fence panels, and the entire flower bed is in the shape of a rectangle.

Now, to know how many panels of this picket fence to buy, I know that we need to find the perimeter or the distance around this rectangle.

So Harper, I think our first step is going to be to measure the length and the width of our rectangular flower bed.

Okay, so I need you to be my big helper.

- Mhm.

- Hold that part of the measuring tape, hold it up.

And lay it down.

- 50?

- 50 inches, good job.

Okay.

Hold that end and lay it down.

22, 22 inches for the width.

Thank you, big helper.

Okay, so we know the length, we know the width, now we can calculate our perimeter.

Perimeter is equal to 2 times the length, plus 2 times the width.

So for this flower bed, that means 2 times 50 inches, plus 2 times 22 inches.

That means that we would need 144 inches of picket fence.

But I think we need to convert that to feet.

Fences are usually sold in sections that are about 8 feet long.

Okay, so 144 inches of picket fence panel, divided by 12 inches a foot, that would give us 12 feet.

- Mhm.

- Now, let's divide that by the number of feet in one picket fence panel.

So that would be 8.

Then we'll know how many picket fence panels we actually need to make the new flower bed.

12 feet divided by 8 feet is about one and a half panels.

But you don't ever go to the store and buy one and a half of something, do you?

Okay, so to be safe, let's round up, and we'll buy two 8-foot panels.

Okay, Harper, now we know how much fence to buy, but here's my question.

Are we sure that we want the flower bed to be the same size?

- No, I think we should get one twice as big.

- Twice as big?

'Cause it's kind of overflowing with flowers, isn't it?

I think that's a good idea.

Okay, so the length of our first flower bed is 50 inches.

If we're going to double that and make it twice as big, we'll multiply 2 times 50.

So our new length would be 100 inches.

And the width of this flower bed is 22 inches.

So to double that, we'll need to multiply 2 times 22, and our new width would be 44 inches.

Okay, now let's calculate the perimeter of our new, bigger flower bed.

Perimeter is equal to 2 times length, plus 2 times width.

So for the new flower bed, that's 2 times 100, plus 2 times 44.

Okay, so for our big new flower bed, we will need 288 inches of picket fence.

Now, again, let's divide that total number of inches by 12, so we know how many picket fence panels to use.

288 inches divided by 12 inches and 1 foot equals 24.

And now let's divide that total, the number of feet, by 8, so we know how many picket fence panels to use.

24 feet divided by 8 equals 3.

So, Harper, we need three 8-foot panels of fence if we're going to make one twice as big.

Are you excited?

Yeah, me too.

Now, once we get the perimeter of the garden built, we're going to need to fill the area inside with new flowers, and you know what that means?

An excuse to go shopping.

(laughing) Okay, well, that's about all the time that we have for today.

Magnificent mathematicians, I hope that you had fun growing your brain with us, and I hope that you get to get outside today and that you have a beautiful day like we're having.

You want to say goodbye to everybody?

We'll see you soon on Rise and Shine.

Bye!

♪ Let's go to class, it's a blast ♪ ♪ You're a great student ♪ ♪ So we know that you can do it ♪ ♪ Shine ♪ ♪ Get up off your feet ♪ ♪ It's time to rise and shine ♪