(bright music) (window screeches) - [Children] Math Mights!

- Welcome, Third Grade Math Mights.

My name is Ms. Askew, and it's that time, time to have fun with math.

But before we begin, let's check out our plan for today.

First we're gonna do a Mystery Math Mistake.

And after that, we're going to learn how to locate non-unit fractions.

Before we begin, let's warm up our brains with a Mystery Math Mistake.

Oh, no, it looks like our Math Mights have all of their strategies mixed up.

It's your job to help them solve the problem.

You are gonna use your magnifying glass to take a problem that you are familiar with and find that math mistake.

Our problem for today is 108 - 79.

Now, Springling, remember, likes to take friendly hops on the number line, but she's all mixed up.

So, let's see if we can't find Springling's Mystery Math Mistake.

First we start at 79, and we're gonna take a hop to a friendly number, a decade of 10.

So we're gonna go to the number 80.

Hop, Springling, hop.

That distance from 79 to 80 is one.

Now we're gonna take another friendly hop to another friendly decade on our number line, which is going to be 100.

What is the distance between 80 and 100?

Hop, Springling, hop.

That's 10.

And finally we're going to hop from 100 to 108.

What is the distance between 100 and 108?

Hop, Springling, hop.

It's eight.

Now we're gonna add these three numbers together.

1 + 10 + 8 = 19.

108 - 79 = 19.

Okay, Third Grade Math Mights, did you use your magnifying glass to find the Mystery Math Mistake?

What do you think about my math?

Did you find something?

Let's see what our friends Imani and Elise think.

Imani says, if I added 79 + 19, it doesn't equal 108.

Elise says, the distance between 80 and 100 is 20, not 10.

So the answer would be 29.

Were you able to find that same mistake?

Let's take a closer look at our white board and correct it.

Imani says, 19 + 79 does not equal 108.

She's correct.

And Elise noticed that the distance between 80 and 100 is not 10.

The actual distance between 80 and 100 is 20.

Springling also agrees.

That's why she's right side up again.

So instead, we're gonna add 1 + 20 + 8.

And that gives us the answer of 29.

So 108 - 79 = 29.

Great job, Elise and Imani, finding that Mystery Math Mistake.

Third Grade Math Mights, were you able to find that mistake as well using your magnifying glass?

When you are able to find errors in math problems that means your understanding of math is getting a lot better.

So now let's move on and check out our I Can statement for today.

"I can locate non-unit fractions on the number line."

Third Grade Math Mights, finding non-unit fractions on a number line can be a little bit difficult.

But I'm gonna try to make it fun for you by playing a game called Number Line Scoot.

Here's how you play that fun game.

Every player gets their own game board, and it has five different number lines.

If we look at these numbers lines they've been partitioned into halves, thirds, fourths, sixths and eighths.

Each player places their cube on the number zero.

Now don't worry, if you don't have a cube, you can use whatever's lying around.

It could be a penny, a Cheerio, a ripped up piece of paper.

It really doesn't matter.

The next step is for each player to take turns rolling a die.

Once you roll that die, you are gonna use that number to record it as a numerator on your recording sheet.

Now, you can choose to either have six halves, six thirds, six fourths, six sixths or sixth eighths.

The object of the game is to try and get your cube or whatever object you use to the end of your number line.

So I think on my first roll, a good spot would be for me to have six sixths.

Now that I have six sixths, I have to find the appropriate number line so that I can move that many spaces.

Now I can locate the number line that is partitioned into six.

So I'm going to move my marker six tick marks.

1/6, 2/6, 3/6, 4/6, 5/6, 6/6, which is the same as one whole.

Now it's time for my second roll.

And I rolled a six.

So, do I have six halves, six thirds, six fourths, six sixths, or six eighths?

I'm gonna choose six halves.

So I'm gonna find the appropriate number line, which is divided into halves, and I'm gonna move my counter.

One half, two halves, three halves, four halves, five halves, six halves, which is the same as the whole number three.

Third Grade Math Mights, are you having as much fun as Ms. Askew is having?

Now remember, the object of the game is to get to the end of your number line so that you can collect a marker.

And the person that has the most markers at the end of 20 rolls is the winner.

All right, let's go for that third roll.

I have two, so my numerator is two.

Should I put it at two halves, two thirds, two fourths, two sixths or two eighths?

I think I'm gonna put it at two halves.

Because I rolled the number two, I have to find the number line that has halves and move it two halves.

One half, two halves, and I end at four.

I'm going to collect my cube and give myself a point.

Then I'm going to replace that cube and start it at zero.

Did you have fun learning that new fraction game, Third Grade Math Mights?

I sure did.

Now remember, the object of the game is to scoot your marker the furthest that you can along that number line.

And after 20 rolls, the player that has collected the most counters wins.

Using what we've learned with that fun game about non-unit fractions, let's locate 3/4 and 6/4 on the number line.

Let's see how Imani does this.

What do you know about 3/4 and 6/4?

Imani says, they both have fourths.

I know six is more than three.

When I see 6/4 I also know that that fraction is larger than one, just like we discussed.

Imani says, I took the number line and divided it into fourths, then labeled the fractions.

Let's map out Imani's thinking on the white board.

This number line starts at zero and it stops at two.

We're going to partition this number line into four equal parts.

Let's start with zero to one.

We're gonna put three tick marks here because the fourth tick mark has already been placed.

This means it has been divided into fourths.

I can also check it by taking my hops.

I'll start at zero, which is my starting point, and hop one, two, three, four.

Now I want to label those tick marks.

This is 1/4, 2/4, 3/4, and one whole makes 4/4.

I'm going to continue to partition my number line into fourths.

But 6/4 is more than one whole because the six in the numerator is larger than my denominator, which is four.

First let's partition from one to two into four equal parts.

One, two, three and four, the tick mark has already been drawn for us.

Now I'm going to double check by taking my hops.

Starting at one, one, two, three, four.

Let's label those tick marks.

We have 4/4.

Let's continue on.

5/4, 6/4, 7/4, 8/4.

8/4 is the same as the whole number two.

Now let's go back and locate each of those fractions.

3/4, we put our point here.

And 6/4, we put our point here.

That wasn't too bad, was it, Third Grade Math Mights?

Locating those non-unit fractions on the number line is kind of like continuing to count on, on a regular number line.

Now that you are able to label those fourths, let's try labeling eighths.

Do you think you can locate and label 7/8 and 12/8 on a number line?

How would you partition the number line?

Let's see what Elise thinks.

Elise says, the denominator is eight, which tells us how many parts to split it into from zero to one.

She's going to look at the number line and divide it into eighths and then label the fractions.

Let's do that together.

This number line starts at zero and stops at two.

We're gonna label the eighths from zero to one.

That means I should have seven tick marks.

One, two, three, four, five, six, seven, because the eighth tick mark is already there.

I can double check that by taking my hops.

Starting at zero I want to make sure I have eight hops.

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

Now I'm going to label those tick marks.

1/8, 2/8, 3/8, 4/8, 5/8, 6/8, 7/8 and 8/8 is the same as one whole.

I'm going to continue to partition my number line into eighths by starting at one and stopping at two.

Again, because it is eight, I only need to have seven tick marks.

One, two, three, four, five, six, seven, because the eighth tick mark is already there.

Let's double check by taking eight hops.

Starting at one, one, two, three, four, five, six, seven, and eight.

Let's continue to label those tick marks.

We left off at 8/8, so now we have 9/8, 10/8, 11/8, 12/8, 13/8, 14/8, 15/8 and 16/8.

16/8 is the same as two.

Now we are going to locate 7/8 and 12/8 on the number line.

Here's my point for 7/8, and here's my point for 12/8.

Excellent job, Third Grade Math Mights, locating non-unit fractions on a number line.

It's so very important to be precise when you are partitioning a number line so that you are able to correctly locate and label those fractions.

Now let's play a fun game called Guess My Fraction.

I'm going to partition a number line, then locate and mark a spot, but I'm not going to label it.

You get to guess what the fraction is!

Here's my number line.

It starts at zero and ends at two.

Do you see where I located my point?

I wonder if you can figure out using our strategies what fraction goes at that point.

Let's take a look and see what Elise thinks.

Elise says, I think your fraction is 4/3.

Let's take a closer look using our white board to explain Elise's thinking.

Our number line starts at zero and it ends at two.

Now, we are going to label this as thirds, because Elise thought the fraction was 4/3.

We have two tick marks.

We don't have to make a third tick mark because it's already there.

I'm gonna double check with my hops, starting at zero and hop one, two, three.

Let's label it.

1/3, 2/3, 3/3, which is the same as one.

Now remember, we learned that if the numerator is less than the denominator, it's less than one.

We're gonna continue on our number line, and because we are going beyond one, I bet you our numerator is going to be larger than our denominator.

Starting at 3/3, we're gonna go to 4/3, 5/3 and 6/3.

Elise is correct.

Our number, or our point, is at 4/3.

How would you like to play that same game with a friend of yours?

Well, you can.

It's your turn now to play a fun game called Guess What That Labeled Fraction Is.

Third Grade Math Mights, I had an awesome time working with you, learning about non-unit fractions.

I hope you come back soon to join us again.

(bright music) - [Child] Sis4teachers.org.

Changing the way you think about math.

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