(upbeat music) - One, two, three, four, five.

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

What an adventure we are on today.

It is math time.

I hope you're excited because I am.

Now, we're talking about comparing numbers today.

And let's think through how many I got when I was hitting that ping pong ball.

The first time I got five, the second time I got up to seven.

So which one was greater?

Well, the seven, right.

I got all the way past five and then two more, six and seven, and we made it.

So today we're talking about comparing numbers and how we can see it, how we can draw it out and visually represent that.

Maybe you like to draw pictures.

You've got a chance to do that today.

So let's get to our problem.

We've got two good problems for you today and let's do it.

So our first one, we have 10 plus 10 plus five.

And how does that compare with 40 minus 10?

All right.

So here's our first problem.

And we can think about, when we're comparing numbers, we can think about the symbols that we might use.

We might say, hey, one number is greater than another number, or it's less than.

And how can we show that?

Remember those symbols greater than, less than?

What about equal to?

What if they're the same?

But before we can decide that, we have to figure out, well, what does 10 plus 10 plus five equal?

So let's start there.

I know that I can draw this out and say, you know what, 10, I'm going to represent with those 10 sticks.

That rectangle right there that represents 10."

But I have two 10.

So I've got to draw out two of those.

Plus five ones, right.

So one, two, three, four, five.

Now we can count all these up together.

And I have 10 plus another 10, 20.

21, 22, 23, 24, 25.

Okay.

So our left side over here is the same as 25.

Now what about the right side?

If I go over to the right side and I say, you know what, 40 minus 10, how could I draw that out?

Well, 40 I know is made up of groups of 10.

So I need a 10, 20, 30, 40 and we've now made it to 40.

But it says minus 10.

And remember subtraction is when we're taking things away or we're removing it.

So what I can do is I can say, you know what?

I have four groups of 10.

I have to take away a group of 10.

So I'm going to put an X on there and say, it's gone.

So now it's gone and I'm up to, how many do I have left?

10, 20, 30.

So I had 25 on one side and I have 30 on the other side.

So how do those compare?

Well, I know that 30 is greater than 25.

There was three groups of 10, over here there's only two groups of 10 plus five ones.

So I could write that in and say 25 is less than 30.

Right?

Okay, and we've got it.

But by how much?

How much greater is 30 than 25?

And we could start at 25, maybe on a number line.

You could draw this out and say, well, how do I get to 30?

Well, I know that I've got to add, and I can add by ones to get there, or you might be able to add by other numbers too, but let's start with ones and say, if I add one, I get to 26.

Add another one, I'm at 27 and keep going, add one more, add one again and add one there.

And now we've added five altogether.

And we're up to 30.

That means 30 is five greater than 25, man.

You guys are doing awesome.

Let's do one more.

Okay.

This one, we have five 10s.

And how does that compare with 30 plus five?

Well, if I look at that, I can draw this one out too.

Five groups of 10.

Well, I've got to represent that with my 10 sticks again.

So 10 20, 30, 40, 50.

We're working with some big numbers here, 50.

And how does that compare with the other side, 30?

I know I need three groups of 10, right.

10, 20 and 30, but I also have five ones.

I got to add those into.

So 31, 32, 33, 34 and 35.

Okay.

How do these compare?

Well, let's look at a number line.

Okay.

If I have 35, how much is it a way from the number 50?

Well, we could add on like we did in the first one, but we could also subtract.

We could start at the number 50 and go backwards.

How are we going to count backwards?

You could count by ones.

You could count by fives.

You can count by tens, right.

Because if I go back from 50, let's take 10 away.

Now let's count backwards.

50 we're down to 40.

Okay, we got to go a little bit more to 35.

40 and then take five away and I'm at 35.

So 10 and five together made 15.

It's 15 greater than 35.

So we know that five 10s is greater than 30 plus five.

Ooh, I'm telling you, this is a major adventure we are on.

And I'm so glad that you're with me because we are problem-solving and thinking great today.

So keep learning, keep problem solving and I'll see you again real soon.

(soft music) ♪ Its time to rise and shine ♪