(playful music) - [Children] Math Mights!

(playful music) - Welcome, second-grade Math Mights.

My name is Mrs. McCartney.

I'm so excited that you've joined us today to learn about math.

Today in our plan, we're going to first start off with a Mystery Math Mistake, and then we're going to go into fractions, learning about halves, thirds, and fourths.

Let's start out warming up our math brain with our Mystery Math Mistake with the Math Mights.

Oh, no, what has happened to our Math Mights?

They all seem to have all of their strategies confused.

During our Mystery Math Mistake, what you're going to do is I'm going to show you a problem that one of our friends did in Mathville.

You're going to keep your magnifying glass on to see if you can find the Mystery Math Mistake.

Today, our friend D.C. has come to solve a problem.

Oh, no, look at D.C.

He's all upside down.

I think that he might have something wrong with his strategy.

I wonder if you can figure out the Mystery Math Mistake.

D.C. told you when he wanted to solve this problem, he wanted to decompose the 13 into one and 12.

When he circle the one and added it to the 48, he got a friendly decade number 50 and then he added 12 more to get the answer of 62.

What do you think?

Did D.C. solve that problem right?

Did you see a Mystery Math Mistake?

Let's see what our friends Shanda and Kelly thing.

Shanda says, "I think 48 needed two more to get to 50, which is a friendly decade number."

Kelly said, "D.C. should have decomposed 13 into two and 11.

That would make it 50 plus 11 equals 61."

Did you find that Mystery Math Mistake that our friend Shanda and Kelly found?

Let's take a look to see where the error is that D.C. made.

D.C. is already feeling better by you helping him with the Mystery Math Mistake.

It looks like when he decomposed 13 into one and 12, Kelly was right.

One plus 48 does not equal 50.

We need to change that.

Even though one plus 12 does equal 13, it isn't decomposed in a way to help us make a friendly decade number.

If we go back and fix it, we're going to decompose the 13 into two because 48 needs two more to get to 50.

And when we take two out of 13, we're left with 11.

This way, when we circle the 48 plus the two, it does equal 50, but instead over here, we're left with 11, making the answer 50 plus 11 equals 61.

Great job trying to figure out that Mystery Math Mistake.

If you can figure out mistakes in math, it means that you're getting smarter and smarter with the strategies that we're working on.

Let's check out our I can statement for the day.

I can partition circles and rectangles into halves, thirds, and fourths.

Check out these four images, A, B, C, and D. Which one doesn't belong?

All of those shapes have different partitions in them, which means they're divided in different ways.

Do you think you could pick out which one might not belong?

Let's check out to see what Shanda and Kelly think.

Shanda says that A doesn't belong because it's the only one that doesn't have equal parts.

Let's take a look at A. I can see a partition line going through here.

If I were to think about this maybe as a big pizza or a piece of a brownie, I certainly wouldn't think that this would be even.

I agree with Shanda.

When we look at these pieces, they're all partitioned or broken up into even slices.

As same as C, the triangles are both equivalent or the same, and then our circle is also divided into equal parts.

Let's see what Kelly thinks.

"B doesn't belong because it's the only one that does not have one shaded part."

In A, C, and D, we see that one section is shaded.

When we look at B, Kelly is correct.

This shape does not have any parts shaded.

Shanda says that C doesn't belong because it's the only one that is not split into four parts.

If we look at A, there's four parts even though they're not equal.

We see four parts here in B.

We also see four parts here in D. She's correct.

When we look at C, it's only partitioned into two parts.

Kelly says, "D doesn't belong because it's the only one that is not a quadrilateral."

Boys and girls, do you remember what a quadrilateral is?

We talked about this.

It has four corners and four sides.

Let's check it out.

Kelly is saying that C is the only one that's not a quadrilateral.

She's correct, because it's a circle.

A, B, and C all have four sides and four corners.

That was really great wonders and notices as we start to look at the idea of fractions.

Today, we're gonna talk a lot about partitioning rectangles and circles, similar to the images that you see here.

Here we have our rectangle.

I want to be able to take this piece and I want to be able to fold it in two equal parts.

I'm going to go ahead and fold it this way so that I can make sure that it's lining up and both sides are equal.

When I put this fold here and open it back up, you can see that I took the whole rectangle and split it into two equal parts.

This part is half, and this part is half.

Together it makes a whole.

We took that rectangle and folded it into two equal parts.

Do you think we can fold rectangles in other fractional parts?

Let's see if we can take the rectangle and fold it into three equal parts.

How should I go about doing this?

I think I'm going to fold this into three parts.

I'm gonna do one part, and then I'm going to do two parts.

What do you think about what I just folded?

Is this an example of folding it into three equal parts?

One of the things you have to be careful with when you're looking at fractions, is you want each of the sections to be equal.

Would it be fair if I took a nice, big pan of brownies and I only gave one friend this size, and one friend this size, and then another friend got this big chunk?

That wouldn't be fair.

So when we're looking at dividing or partitioning or even folding rectangles, it's important that they're in equal parts.

I think we should try this again.

Let's take a look at this rectangle.

I'm gonna go ahead and fold it just like a letter so that I can try to create three equal parts.

I'm gonna fold this very carefully.

Sometimes it's hard to make them completely equal, but we definitely want them to look that they're the equal size.

I've partitioned this into three equal pieces.

This is 1/3, 1/3, and 1/3.

We've now been able to take the rectangle and fold it two different ways: in halves and in thirds.

Let's see if we can try one more way.

Here I have the rectangle again, and this time, I want to be able to fold it into four equal parts.

So I'm going to go ahead and fold it in half, like we did before, and then I'm going to fold it in half one more time, being very that I'm making these equal so that if we were to share this, they would be divided into four equal parts.

Let's see if we could take that rectangle.

I see one, two, two, three, four equal parts.

Each part is known as 1/4.

There's 1/4, 1/4, 1/4 and 1/4.

Altogether, it equals one whole and it is broken into four equal parts.

Do you know there's another name for fourths?

We can call that quarters.

Don't think of money here, but we want to think of slicing something in quarters.

So if we look here, fractions have lots of different names.

We can fold something into two equal parts, and the name of each part is halves.

If we fold something into three equal parts, it's known as thirds.

If we fold something into four equal parts, it's known as fourths.

Let's take a look now as we look at circles.

Noah is looking at circles that have been decomposed into halves, thirds, and fourths.

Let's see if you can figure out which ones are not examples.

Here I have the picture that Noah was looking at of the halves.

If I were to have a pie or a pizza here and I got half, that would be fair.

That's a good example of halves.

When I look at this one, it is split into two pieces, but it is not in equal pieces.

So this is not an example of halves.

This circle is also similar.

Imagine only getting that little piece of pizza or pie.

You would want to be able to divide that evenly.

So this is not an example of halves.

Now let's take a look at the next one.

This one's going to look more to see if they're divided equally into fourths.

Here we have a circle divided into four parts.

Boys and girls, are those equal?

Absolutely not.

This is not an example of fourths.

Now this is divided nicely.

One, two, three, four, and it's even, so that's a really good example of fourths.

This one is divided equally, but it does not represent fourths because they are not four equal parts.

So we're going to cross that one off too.

Do you think you can keep going and look now at circles with thirds in them?

Let's take a look here.

I see one, two, three, four.

Wait a minute, are they trying to trick us?

This is supposed to be in thirds.

This is not an example of thirds.

This piece is cut into three parts, and they are equal, so that is a good example of thirds.

This one, if I look, I would feel cheated if I got these outside pieces, because they are not equal.

It's broken into three parts, but they aren't equal.

Therefore, this is not an example of thirds.

Great job on checking out those circles to see how they were partitioned.

You have to be careful to make sure they're in equal parts.

Let's take a look at this circle.

Do you think you can partition this circle into thirds?

I have a circle here on the dry erase board.

If I were to cut this out, you might have a difficult time putting this into thirds.

Let's check out to see how our friends Claire and Diego partitioned the circle two different ways.

Which of these circles is partitioned into thirds?

Based on what we talked about with the characteristics of thirds, which one do you think is partitioned into thirds?

Let's see what Shanda and Kelly think.

Shanda says, "Both circles have been partitioned into three parts."

Let's check.

Claire's is in one, two, three parts, and Diego is in three parts.

Shanda is correct.

Our friend Kelly says, "I agree, however, Clare's is not in thirds because it's not partitioned into equal parts."

Let's take a look here.

Although it is in three parts, it does not follow the definition of thirds like Diego's does because these are equal parts.

Great job, girls, picking out which of those circles are partitioned into thirds with equal parts.

Let's see now if we can split the rectangle into thirds, but this time, I want to see if you can shade one part.

I have the rectangle, but I want to be able to partition it into three equal parts.

So I have to be careful.

I'm drawing my lines.

If I made my first line here, I have one section, but when I draw this line here, it's gonna provide with the middle section and here.

We want to be able to shade one of those parts.

We have three parts, and so I'm going to shade in blue this part.

Let's see if we can tie some language to what we just created on our rectangle.

It says that each part of the rectangle is called a what?

Each part of the rectangle that we created is called a third.

Let's talk about how many parts were shaded.

That would read a third of the rectangle is shaded.

That was great.

We were able to take that rectangle, not only put it into thirds, but we were able to shade a third of that shape.

It's now your turn to be able to do what we've been doing in the show today by doing a game called Split the Shape.

You can do this with a friend.

You're going to spin on the spinner, and it's going to tell you if you're going to partition your circle, rectangle, or square into halves, thirds, or fourths.

Boys and girls, I've had so much fun hanging out with you today during our Math Might show.

From our Mystery Math Mistake where we helped D.C. get back on track, to learning all about fractions and learning about equal parts.

I sure hope you join us next time.

(playful music) (mellow music) - [Boy] SIS4Teachers.org.

(air whooshing) Changing the way you think about math.

(bright music) - [Narrator] The Michigan Learning Channel is made possible with funding from the Michigan Department of Education the State of Michigan, and by viewers like you.

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