(bright music) (spring boings) (glass squeaks) - [Children] Math Mights!

- Hey, Math Mights, welcome back, and if it's your first time, 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're going to be solving a Mystery Math Mistake, and then, we're going to compare lengths.

Let's warm up our math brain with a Mystery Math Mistake.

Oh, no.

All of our Math Mights have gotten their strategy all mixed up, and I need your help to find their mistake.

Okay, here's how it works.

I'm going to act out a math problem with a concept that you're familiar with, and you're going to use your magnifying glass to try and find my mistake, not a real magnifying glass, one that looks like this.

You can use your hand and be a math detective.

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

So here's my problem.

I have 27 plus 44, and my friend, Value Pak, is going to help me solve that problem.

Remember Value Pak?

Value Pak wears his value on his belly, and when he clicks apart, we can see his tens and his ones.

Let's start by decomposing the 27.

I'm gonna pull apart the 27 and show 20 and seven, and then I'm going to decompose the 44 to 40 and four.

I'm going to add the tens, 20 and 40 equals 60.

And then I'm going to add the ones, seven plus four equals 10.

And I know 60 plus 10 equals 70.

I know that 27 plus 44 equals 70.

Let's see what our friends Dennis and Huan have to say.

Dennis says, "It looks like the tens were added correctly."

Huan says, "I think you added the ones incorrectly.

Seven plus four is 11, not 10, so the answer should be 71."

Were you able to notice the Mystery Math Mistake, like my friend Huan?

Let's help Value Pak make that correction now.

Hey, check it out.

Value Pak is right side up again.

We're going to fix that mistake that Huan told us about.

We have 60 plus 10, but remember, Huan said that seven plus four doesn't equal 10.

It equals 11.

So we're going to put the 11 right here.

And first grade Math Mights, it's okay if we make mistakes in math.

That's a way of learning.

So it was a good catch by Huan.

Let's solve it the correct way.

60 plus 11 equals 71.

Great job noticing the details and finding that Mystery Math Mistake.

Now we're going to check out our I can statement of the day.

It says, "I can compare and order objects by length."

Take a look at these three pencils.

What do you notice?

What do you wonder?

My friend Dennis says, "I notice there are three pencils that all look the same.

Pencil A and Pencil B are the same length."

Huan says, "Pencil C looks longer, but isn't lined up with the others."

Dennis says, "I wonder why Pencil C is raised up higher than the others."

And Huan says, "Are they all the same length?"

Well, which pencil do you think is the longest?

Dennis says, "It looks like they're all the same, but it's really hard to tell."

Let's take a look at my pencils that I brought for us today.

You can see that I have three pencils that are similar to the ones that we saw on our slide.

This time, I have three pencils that are lined up the same, and this pencil looks a little bit longer.

Well, Math Mights, when we're comparing lengths, we need to always start with an endpoint.

An endpoint is kind of like when you're getting ready to run a race, and everybody starts at the exact same spot.

That's what we're going to do here with our pencils.

We're going to start them all at the exact same place.

I'm gonna use my marker, and make an endpoint for all three of our pencils.

So I'm gonna draw a straight line.

Then I'm going to take each of my pencils, and line them up as close as I can to that endpoint.

Now you can see all three pencils are touching that endpoint.

And when I take a closer look, it looks like all three pencils are the exact same length.

So remember, first grade Math Mights, that new word endpoint, we always want to start our objects at an endpoint.

Now we're going to compare two more objects.

What comparison statement can you make about the pencil and the crayon?

Dennis says "The pencil is longer than the crayon with it side by side.

The crayon is shorter than the pencil."

Huan says, "They are different colors.

The pencil is made of wood and the crayon is made of wax."

I really like the way that Dennis used the words longer than and shorter than to compare the crayon and the pencil.

Let's take a look at a couple of objects that I found.

I found a stick and a clip that we can compare lengths, using the words shorter than and longer than.

It looks like the stick is longer than the clip.

My first sentence says, "The hmm is longer than the hmm."

Let's put the word stick at the beginning.

The stick is longer than the clip.

Now I have another sentence that says, "The hmm is shorter than the hmm."

I think that the clip is definitely shorter than the stick.

So I'm going to write the word clip in the bottom sentence.

The clip is shorter than the stick.

Those are great comparisons, Math Mights.

Let's keep working and comparing more objects.

Now I want you to choose an object you could compare with these nine connecting cubes.

Hm, I wonder what you have where you're at that you could grab.

You could grab something that's longer than the cubes, or you could grab something that might be shorter than the cubes.

Let's see what my friend Dennis grabbed.

Dennis says, "I chose a marker.

The marker is shorter than the tower of cubes."

I wonder what object you picked to compare with the nine connecting cubes.

I chose a highlighter.

Let's take a look at mine.

You can see that I have the nine connecting cubes and a highlighter.

The first thing that you have to remember, like we talked about a little earlier, is that they have to be lined up at the endpoint.

We don't ever wanna forget that.

So you can see that I lined up, if I drew that imaginary line with my finger, I have the cubes and the highlighter lined up at an endpoint.

I can see just by looking at it that the cubes are longer than the highlighter.

Great job comparing with connecting cubes.

We can also compare with other things.

Let's take a look at this.

Let's fill in the blank.

We can use an object to compare if something is longer or shorter than, like we could try using a body part.

On this page, you can see that I have a foot and a finger.

The top phrase says, "The hmm is shorter than my foot."

Now we don't all have the same size feet, so for this part of the activity, I want you to use your own foot.

Then we're going to compare something that is longer than your pointer finger.

Well, you might wonder, what is my pointer finger?

On your two hands, you have two fingers right here that you would usually use if you wanted to point to something.

You know, sometimes when we're talking on camera, and I go, "Hmm, I wonder what I'm thinking."

Those are your pointer fingers.

Let's try and fill in those blanks, and see what my friend Dennis has to say.

Dennis says, "The tower of cubes is shorter than my foot."

And Huan says, "The pencil is longer than my pointer finger."

Those are great comparisons, boys.

Can you find three objects, and order them from shortest to longest?

Think about something you might have near you.

What do you think you could find?

I found three objects near me.

I happened to find a stapler, scissors, and a hole punch.

Let's take a look on the overhead, and see if we can order the objects from shortest to longest.

I have the stapler, scissors, and a hole punch.

The very first thing I'm going to do is make that endpoint.

So I'm going to slide my three objects out of the way.

I'm gonna make that endpoint.

Remember this helps our measurement to be accurate.

Then I'm going to look at my objects.

It looks like the hole puncher could be the shortest.

So I'm gonna line that up at my endpoint.

Then I think I'm gonna try the scissors.

Starting at the endpoint, the hole punch is shorter than the scissors.

Now I'm going to grab the stapler.

Hm.

That doesn't look right.

I think I have to change a couple of my objects.

I'm gonna move my scissors, and put the stapler there.

The hole punch is shorter than the stapler, and the hole punch is shorter than the scissors.

So you can see that I have ordered these three objects from shortest to longest.

I wonder if you were able to line up your three objects from shortest to longest?

What would happen if the objects were not lined up?

Well, my friend Huan says, "One might look longer even though it wasn't."

You can see that the cubes are not at the endpoint, Math Mights.

Now, remember, when you are comparing objects, you have to make sure that they are lined up at the endpoint, so that you can get an accurate comparison.

Great work, friends.

Now, can you find three new objects, and order them from longest to shortest?

I'll give you a quick sec to see if there's something that you can find near you.

I found three objects.

I found a base-10 block, a straw, and a noodle.

Just like before, I'm going to make an endpoint.

I'm gonna make it as straight as I can, and I'm going to take my three objects, and figure out which one is the longest.

I think the noodle might be the longest, so I'm going to line it up really carefully against my endpoint.

Then I'm going to put my base-10 block.

Well, I can definitely see that the noodle is longer than the base-10 block, but I still have to add in my straw.

Hm, that doesn't look right.

I think I need to switch a few things around.

What do you think?

Yeah, I think I need to move the base-10 block, and put the straw up there.

Now you can see the noodle is longer than the straw, and the noodle is longer than the base-10 block, and the straw is longer than the base-10 block.

So now you have ordered these three objects from longest to shortest.

Great job, Math Mights.

I have one more way that we're going to order our objects.

We're going to take the three objects, and order them from tallest to shortest.

Let's see if we can give that a try.

What statement can you make that compares the length of objects?

My statement says, "The hmm is taller than the hmm and hmm."

So I took those same three objects, and I put them in front of me on my whiteboard.

This time, instead of saying what is longest and shortest, we want to find out what is tallest.

So think about you and your friends.

If you're standing at school, you might wanna get in line from the tallest to the shortest.

That means we're standing up.

We're not really laying on our side.

So this time, I'm going to draw my line down here at the bottom.

We've kind of said this is our starting line, or maybe the endpoint.

And what we're going to do is look at our three objects a different way.

I'm going to move them so that they are up and down, like they're standing.

I think that the fettuccine noodle is the tallest, and I think it might be taller than the other objects.

Then I'm going to put my base-10 block.

The fettuccine noodle is taller than the base-10 block.

I'm going to grab my straw.

Hm.

I think I'm going to need to switch things around.

I'm going to put the straw in the middle, because the fettuccine noodle is taller than the straw, and the fettuccine noodle is taller than the base-10 block, and the straw is taller than the base-10 block.

So now I have to go down and put that information in my sentence.

The, I'm going to write the word noodle, the noodle is taller than the straw and the block.

Math Mights, now it's your turn.

It's time for you to compare the length of objects.

I had a great time with you today, Math Mights.

We did so many things.

We compared the length of objects, and solved a Mystery Math Mistake.

Until next time, kiss your brain.

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Changing the way you think about math.

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