(playful music) (electronic whirring and dinging) - [Children] Math Mights!

- Hey, Math Mights.

Welcome back!

And if it's your first time here, I'm Mrs. Markavich, and I'm so excited you're here with me today.

Let's check out our plan for the day.

Today, we'll be solving a mystery math mistake.

And then we'll be measuring with tools.

Let's warm up our math brain with a mystery math mistake.

Oh no!

All of our math mights got their strategies all mixed up.

And I need your help to help me solve the mystery math mistake.

Here's how it works.

I'm gonna act out a math problem of a concept that you're already familiar with.

And then you're going to use your magnifying glass to see if you can find the mistake I made.

Not a real magnifying glass.

You can make one with your hand like this, and you can be a math detective.

And then I want you to make sure you can explain your reasoning.

So let's take a look at what I've got here.

I have the problem 17 plus 36.

And look at our friend DC.

He is upside down and all turned around.

Remember, DC is a math might that lives in Mathville, and he loves friendly numbers.

So he decomposes the numbers with his mallet and makes them friendly numbers.

So let's decompose that 17.

I know that if I decompose it, I can make it 14 and 4, because 36 and 3 make 40.

Now I've set up some 10 frames with some counters in them.

I have 17 and I have 36.

I'm going to grab the three that I decomposed.

Move them over here to make the 40.

So now I know that 14 plus 40 equals 54.

So DC thinks that 17 plus 36 equals 54.

Did you figure out the mystery math mistake?

Let's see what our friends Addie and Holland came up with.

Addie says, "17 can be 14 and 3 when you decompose it.

"But something doesn't look right."

Holland says, "I don't think 36 plus 3 equals 40.

"We need to decompose 17 into 13 and 4."

Ooh, good catching that mistake, Holland.

I wonder if you caught the same mistake that Holland did?

Let's help DC fix that now.

This is the part where I made the mistake.

It's not supposed to be 14 and 3.

I actually need to change the way that I decompose the number.

And I need to decompose it into 13 and 4.

And that means I need to change it in my equation as well.

So I'm going to erase my equation and I'm going to write 13 plus 40 equals 53.

But I'm not done yet.

I need to look at my 10 frames.

And you can see that I need to decompose this from 14 to 13.

And now I have 13 plus 40 equals 53.

Great job finding all the details and paying attention and finding that mystery math mistake.

Now it's time for us to check out our I can statement of the day.

Our I can statement of the day says, I can measure length with tools.

Let's take a look at this picture.

What do you notice?

What do you wonder?

Hmm, when I look at it, I see two different colored sets of cubes.

And I also see a pencil, one set of cubes that is shorter than another set of cubes.

Let's see what my friends Addie and Holland are thinking.

Addie says, "I notice the purple tower "is longer than the yellow tower.

"It looks like the pencil is the same length "as the purple tower."

Helen says, "The yellow tower is shorter than the pencil."

Addie wonders, "How much longer is the purple tower "than the yellow tower?"

And Holland says, "How long is the pencil?"

Those were great notices and wonders, girls.

And I really liked your use of the math language.

Now let's see if we can describe the length of the pencil and the cubes.

Addie says, "The pencil is longer than the yellow cubes.

"The pencil is the same length as the purple cubes."

Wow!

That was a great notice there, Addie.

Let's take a look at mine and see if we can discuss the length of the cubes and the pencil.

You can see on mine that I have the yellow cubes, the pencil, and the red cubes.

You can also see that they are all lined up at their endpoints, because remember, in order for us to make an accurate comparison or measurement, we have to line them up at their end points.

When I take a really close look, I can see that the pencil is a lot longer than the yellow cubes.

When I compare the pencil to the red cubes, look at that, they are the exact same length.

So I was able to determine after looking at the yellow cubes and the red cubes that the pencil and the red cubes are equal.

That means they are both the exact same length.

All right, friends.

Now it's time for us to find the lengths of these creepy, crawly things.

Oh boy, I'm not really a fan of creepy, crawly things.

So it's a good thing that I have them on my paper here.

Okay, so you can see in front of me today I brought some cubes with me.

But if you don't happen to have cubes with you, you could find other objects to use.

You could use toothpicks, macaroni noodles, you could use paper clips.

There are so many different things you could use as long as they are all the same size.

So we're going to use the cubes today.

And we're going to start up here with a praying mantis.

I'm gonna take my cubes and measure from end point to end point of this line.

So when I put them on here like this, you can see that they are a little bit too long.

So I need to take some off.

And I'm just gonna set them over there because I'm gonna need them soon.

So now looking at this, I can count and say one, two, three, four, five, six, seven, eight.

The praying mantis is eight cubes long.

And I'm gonna write it on here just so I know for later.

Now I'm going to take a look at this creepy, crawly guy.

He's a dragon fly, and I can see his line goes from here to here.

So just like I did up here, I need to measure from end point to end point.

And you can see that I have too many cubes again.

So I'm gonna snap some off and see if this is a little more accurate.

And you can see that my cubes go from end point to end point.

So now I can count them.

One, two, three, four.

I'm going to write four cubes.

Next, I have another creepy, crawly guy down here.

And I'm going to start with my cubes and line them up at the end point.

Uh oh, but this time it looks like I'm going to need to grab a few more cubes because these don't go all the way to the end point.

I'm gonna get a few more, snap them together and let's take a look.

I think this is definitely much more accurate.

You can see that the cubes go from end point to end point.

Let's count them.

One, two, three, four, five, six, seven, eight.

Huh?

Would you look at that?

This creepy, crawly guy is the same length as our praying mantis up top.

I still have two more creepy, crawly guys to measure.

So let's do that now.

On this side, I have a grasshopper.

I'll lay my cubes down and you can see that my cubes are longer than the line.

So I need to take just a few off.

Let's see if I did that correctly.

You can see from end point to end point, I have one, two, three, four, five, six cubes.

So I'm gonna write down six cubes.

And this last long, creepy, crawly worm is here for me to measure.

I'm going to lay my cubes down.

And I think you can already tell, I'm going to have to get more cubes.

Let me grab the ones that I have on the side, snap them together and see if it will work.

I'm gonna push them nice and tight.

It looks like I am lined up from end point to end point.

Let's count them all.

One, two, three, four, five, six, seven, eight, nine, ten.

Wow!

That was a lot of cubes.

I'm gonna write 10 cubes.

It was really fun measuring all of these creepy, crawly things.

This looks different from everything that we've talked about.

What is the length of the pencil?

How do you know?

Let's take a look at what I have in front of me.

We have always talked about lining up the objects at the end points.

But when you take a look at this one, you can see that it's not lined up at the end points.

It's kind of in the middle of my cubes.

So I'm wondering, how can I make an accurate measurement?

Well, if I look really close at it, what you can see is a right here, the cube kind of ends, and this pencil is lined right up with that end point.

And the same thing at this end point.

So almost if these weren't here and I kind of framed this like this, you can see that the pencil goes from end point to end point.

So I can count the cubes in the middle.

One, two, three, four, five, six.

So I know that the pencil is six cubes long.

So I'm just gonna record that here.

Six cubes.

That was definitely a different way of thinking, but I'm glad we were able to see that I can line the object up at the end point and still get an accurate measurement.

Great work, math mights!

Measure this line with paperclips.

Well, we just finished measuring with cubes.

Now it's time for us to use a different object to measure with.

You know, we talked about before that you could use a toothpick or macaroni, and we maybe even mentioned paperclips.

So let's give it a try.

I have a line in front of me and I brought some paperclips with me.

We still have to do like we've always done where we have to line the paperclips up at the end point.

So I'm gonna start right here like this.

We have to be really careful when we're lining them up.

They have to touch each other just like that and stay as straight as they can on that line.

That was really fun.

Now let's go back and count and see how many paper clips we used.

We used one, two, three, four, five, six, seven, eight nine.

Our line was nine paperclips long.

We measured from endpoint to endpoint and came up with a total of nine.

Great work, math mights!

How was measuring with the paperclips the same or different than measuring with the cubes?

Well, my friend Addie says, Paperclips don't connect.

"You need to be careful about laying the paperclips down.

"They move easier.

"You still start at one end point "and end at the other end point."

That was a great observation, Addie!

You were right.

And I think you could see when I was lining them up, they do move easier Great observation!

Let's check out what some more friends did when they used their math might notebook to measure with some different objects.

Andre says, "The notebook is five paperclips long."

Do you agree or disagree?

Take a really close look at that.

Holland says, "I disagree with Andre.

"His paperclips are not lined up."

That's a great observation, Holland.

You can see, when we're measuring our books or different objects, we have to make sure that we don't leave any gaps or spaces.

Then we won't have an accurate measurement.

Let's take a look at this.

Tyler says, "The notebook is seven paperclips long."

Do you agree or disagree with Tyler?

Addie says, "I agree with Tyler "because they are all lined up and there are seven."

Great observation, Addie!

You're right.

They do go from end point to end point.

And there are seven.

Let's take a look at another one.

Claire says, "The notebook is eight paperclips long."

Do you agree or do you disagree?

Our friend Holland says, "I disagree with Claire "because her paperclips are overlapping."

That's a great observation, Holland!

You're right.

You can see how there's an extra paper clip along the side.

And we can't have the paper clips overlapping or we won't get an accurate measurement.

Now it's your turn to measure with a tool, kind of like we did today.

You could use paper clips or cubes.

First grade math mights, I had so much fun with you today.

We were able to solve a mystery math mistake with our friend DC.

And then we were able to measure with tools.

We used paper clips and cubes.

Until next time math mights, kiss your brains.

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