(enchanted music) (swish sound) (twinkling sound) (creaking sound) (glass squeaking) - [Children] Math Might.

- Welcome third grade Math Might, my friends.

My name is Ms.Askew.

Are you ready to have fun with math today?

I sure I am.

So let's check out our plan for today.

Today, we're going to do a number talk.

And after our number talk, we're gonna be measuring with rulers.

Before we get started, let's warm up our math brains with a number talk.

Now a number talk has three parts.

First, I'm going to pose a problem and you're going to use fractions to solve it.

Second, you're going to try to solve it mentally without using paper and pencil.

And finally, we're going to share out our strategies.

I want you to take a look at these fraction area model papers.

What fractional space is occupied by color.

I wonder, can you come up with multiple fractions that occupy each color?

Let's see what our friends, Landon and Myles think.

Landon says, "I think 1/2 is orange, 1/4 is yellow, and 2/8 are blue.

Let's check that out.

Here I have my area model with different color fraction parts.

Landon says 1/2 is orange.

If I take the other half fraction piece and cover up the other colors, I can take it away and see that half of it is orange.

I'm going to record that, 1/2 is orange.

Next, Landon says, "1/4 is yellow."

The reason why we know 1/4 is yellow is if I take the rest of my fraction pieces and cover them up with 1/4, 2/4, 3/4, 4/4 and take them away, 1/4 is yellow.

I'm going to record that, 1/4.

Landon said 2/8 are blue.

Let's take a closer look at what he means by that.

If I cover the rest of the area model with these fraction pieces, I see that I have eight altogether.

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

Landon saw that two of those eight pieces were blue, which means 2/8 of the area model is blue.

I'm going to record that, 2/8.

Let's see what miles thinks Myles thinks.

Myles says, "I think 2/4 are orange and 2/8 are yellow."

Myles is correct.

If I take the yellow fraction pieces and cover up the orange, we see that 2/4 are orange.

I'm gonna record that, 2/4.

He also says that 2/8 are yellow.

When I cover them up with my blue fraction pieces, I see that 2/8 are yellow.

He's correct.

I'm going to record that, 2/8.

Great job, boys.

Can you think of other fractions that you can use to talk about the colors?

Landon says, "I also think 4/8 are orange."

When I cover up the rest of the orange with my blue fraction strips, I see that 4/8 are orange.

I'm gonna write that down, 4/8.

Myles says, "I think 1/2 is yellow and blue combined."

Wow, that's really different.

Myles is gonna combine two colors to show that it's 1/2?

I wanna see what that looks like.

Myles says that 1/2 is yellow and blue combined.

If I take my 1/2 fraction piece and cover it up, he's right, 1/2 are yellow and blue combined.

As we were looking at that area model, we thought that a lot of those fractions were equivalent.

1/2 is equal to 2/4, 2/4 is the same as 4/8.

We also noticed that 1/4 is the same as 2/8.

Great job on that fraction number top.

Now let's look at our "I can" statement for today.

I can measure length using a ruler marked with halves and quarters of an inch.

Now I would like you to take a look at these two rulers.

What do you notice and what do you wonder?

When I look at those two rulers, the top ruler looks familiar to me but the bottom ruler looks a little different.

Let's see what our friends, Landon and Myles think.

Landon notices the ruler we have been using only labels the whole inches.

Myles notices some of the marks are different on the new ruler.

The 1/4 marks are little shorter than the 1/2 marks.

Those are some really great notices, Myles and Landon.

Do you have any wonders?

Landon wanders why are some of the marks shorter and some longer.

Are all the marks and between the whole numbers 1/4?

Myles wonders, how could I use this ruler to measure?

What would be the length of something that was in between the marks?

We had a lot of great notices and wonders.

We're gonna explore more with that today.

We see two rulers.

The first ruler is familiar to us.

This is the one that we've been using.

The bottom ruler is a little bit different because it has more tick marks.

The longer take mark represents the half.

The shorter tick mark represents a fourth or a quarter.

If we were to read those tick marks, we could say that this is 1 and 1/4.

The second tick mark is 1 and 2/4 or 1 and 1/2.

The third tick mark is 1 and 1/4, 2/4, 3/4, 1 and 3/4.

Now that we have a better understanding of what those tick marks mean, let's see if we can use that ruler to measure.

Kiran and Jada measure a worm.

Kiran says the worm is 4 and 2/4 inches long but Jada says the warm is 4 and 1/2 inches long.

Can you explain how both of their measurements are correct?

What do you think?

Do you think that just Kiran is correct or just Jada is correct, or maybe you think both are correct?

Let's see what Landon says.

Landon says, "Kiran's measurements make sense because you can think about the mark on the ruler at the end of the worm as 4 and 2/4 inches, but you could also think of it as 4 and 1/2."

Landon has some pretty interesting thoughts.

Let's take a closer look.

Our ruler is not to scale.

It has been blown up so that we can see it a lot better.

If I'm looking at this worm, I'm going to measure it from end point to end point.

When I see here, the worm is a little bit further than the number four.

So it's halfway in between the 4 and 5.

So that measurement would be 4 and 1/2 inches.

I can also think of it as 1/4 inches.

This is 1/4, this is 2/4 or 1/4 and 2/4.

So the worm measures 4 and 2/4 inches as well.

Remember third graders, when we are labeling our measurements, we wanna make sure we include the units.

We're working with inches.

So I'm gonna go back, and I'm gonna put the inches on my measurements.

I'm gonna abbreviate it with in because that's the shortened version of inches.

Third graders, it's so important for you to remember that when we are working with measurement, it also has equivalents, just like we learned with fractions.

We saw that with the way that Landon measured the worm on that ruler.

We have four different worms that are different lengths.

Let's measure the worms with our ruler.

We're gonna measure the worm from end point to end point.

And as we can see it measures seven inches.

I'm going to record that as 7 in for inches.

That was a pretty easy measurement.

I wanna try to make it a little bit difficult for you.

So let's check out our next worm.

We are still gonna measure it from endpoint to endpoint.

But when I look at this worm, it's a little bit longer than the 4-inch mark.

So I need to make sure I look at the tick marks that are in between.

Remember, we can count these as 1/4 inches, 1/4, 2/4, 3/4.

So this worm measures 4 and 3/4 inches.

I'm gonna make this a little more challenging for you, third graders.

Is there another way that we can label that measurement?

Let's take a closer look.

If I count the tick marks as 1/4, I can see that there are one, two, three, four, five, six, seven eight, nine, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 19 fourths.

So I can write that as 19/4 inches.

Now we're gonna practice more and measure our third worm.

Looking at our ruler, we're gonna measure from end point to end point.

I see that this worm is a little bit longer than the two inch mark.

Remember, if it's in between the two and the three, this longer take mark is 1/2.

So this worm measures 2 and 1/2 inches.

I'm going to record that 2 1/2 inches.

Thinking about how fractions can be used for measurement.

Can you think of other equivalent fractions that we can use to name the length of that worm?

Let's take a closer look.

We know that we can also call these tick marks fourths.

So if I look at this worm, it's at the 1/4, 2/4 mark.

So I can also measure this worm as 2 2/4 inches.

That was some pretty good thinking, third grade Math Mights.

Do you think you can come up with one more equivalent fraction for the measurement of that worm?

Let's try and see.

Remember, you can also count these as 1/4 marks.

So if I added these all up together I could count one, two, three, four, five, six seven, eight, nine, 10 quarters, or 10/4 inches.

You're doing an awesome job, third grade Math Mights finding those equivalents.

Do you think there's one more equivalent that we can find for the measurement of that worm?

I think so.

Let's try it out.

We can count the half marks on our ruler.

Let's see how many there are 1/2, 2/2, 3/2, 4/2, 5/2.

I'm gonna record that as 5/2 inches.

Wow, we just bound for equivalence to measure that one worm.

Now it's time to measure our final worm.

I'm gonna measure this worm from end point to end point.

I can see that the worm is a little bit past the three and it's in between the three and the four.

So that measurement would be 3 1/2 inches.

I can also measure it using the half marks, 1/2, 2/2, 3/2, 4/2, 5/2, 6/2, and 7/2, 7/2 inches.

Great job using your knowledge of halves and quarters to measure with a ruler.

Now want to measure to find the length and equivalent length of these scissors.

My ruler has been blown up, so it's not to scale.

We're gonna measure that scissors from end point to end point.

And when we do that, we see that the end points stops right in between the five and the six.

So that means this pair of scissors measures 5 1/2 inches.

An equivalent way of measuring that would be 5 2/4 inches.

It measures 5 2/4 inches because we are counting these tick marks as 1/4 inches.

We have 5 and 1/4, 2/4.

Now we're going to measure the stapler and find its equivalent length.

Measuring the stapler from end point to end point, we can see that it measures 4 inches long.

If I use my half tick marks, I can measure it as 1/2, 2/2, 3/2, 4/2, 5/2, 6/2, 7/2, and 8/2 inches long.

Great job with measuring those objects and finding their equivalent length.

Let's continue and measure another object.

Let's find the length and the equivalent length of the hole punch.

When we measure the hole punch, we're gonna start from point and end at this end point.

We see that it measures just slightly past the three.

That tick mark represents the 1/4 inch.

So this paper hole punch it measures 3 1/4 inches.

Now find the equivalent length by measuring the 1/4 inch marks.

one, two, three, three, four five six, seven eight, nine, 10, 11, 12, 13 fourths.

So the hole measures 13/4 inches long.

Now we're gonna take what we learned today and do an activity where you take a ruler, and measure objects and find their equivalent lengths.

You did an awesome job today, third grade Math Mights.

First, we did a number talk with fractions and we compared them.

And then you were able to measure objects and find their equivalent lengths.

I hope to see you real soon.

When we talk more about math.

(enchanted music) (delightful music) - [Student 1] Sis4teahcers.org.

- [Student] Changing the way you think about math.

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