(upbeat music) ♪ Candy and cows ♪ ♪ Cows and candy ♪ ♪ Let's solve some problems today ♪ - Yes.

Today, we've got some great problems for you to solve and I'm so glad that you are here with me because I need some help.

And yes, our problems are some story problems that have to deal with candy and cows.

Now, these are a little bit challenging.

We've got some bigger numbers today so I hope that you're ready.

You may have to warm yourself up.

Maybe do some jumping jacks.

Get yourself loose 'cause your brain needs to be ready to go.

Are you ready?

I am.

Let's jump in.

All right.

So our first problem, let me kind of set it up for us.

We have some candy and we've got some candy in this jar.

So there's 32 pieces of candy in this jar.

What happens if I eat 20 of them?

How many would still be left in the jar?

Can we figure that out?

Well, I bet we can and we can do this in different ways.

So we're gonna think through some different strategies.

But first, we gotta figure out, what operation are we using?

If I'm starting off with 32 and I'm eating 20 of them, what's happening to those 20?

Will they're being taken away or taken out of the jar?

So we need to use subtraction, right?

We've got to take away.

So one of the ways that we could use to kind of solve this problem is we could use some number cubes and I've got some with me today.

So let's think about it.

If I start off with 32, how can we represent the number 32?

Well, I know that 32 is made up of some groups of 10.

Right?

10, 20, 30.

So three groups of 10 and two more ones, right?

That could be 32.

Now, if I'm gonna take away 20, how could I show that?

Well, I know that if I'm taking away 20, 20 is made up of groups of 10 too.

So groups of 10 are really helpful to help us solve problems 'cause I can take away 10, take away a second 10.

There's 20, right?

If I count by tens.

How many do I still have?

Well, I have one group of 10 plus two ones.

So if I count on from 10, 11, 12, we have 12 candy, pieces of candy still left in our jar.

Now, that's just one way to solve it.

Right?

So if you don't have number of cubes, could you still do it?

You bet?

You can draw out your thinking.

So if I take the number 32, 'cause remember we started with 32 pieces of candy and I say groups of 10, you could just draw out those rectangles representing a 10 for each one, right?

So we have 10, 20, 30.

Three groups of 10 plus our two ones and there's 32.

Now, we're saying we're taking away 20.

So if you are drawing this out, how could you show that you're taking away?

You could just put an X through it and say, you know what?

I don't need this group of 10 because we took it out of the jar.

I ate it, right?

It's gone.

So we've taken out one group of 10, but I need to take out 20.

So that means two groups of 10.

So we're gonna take that out and look what we have left.

We still have one group of 10 plus those two ones and we are at 12.

Well, that's what we came up with the first time.

So we got two different ways of solving things, but we came up with the same answer.

Could we do it another way?

I think we can with a number line.

Let's think about that one.

Now, on a number line, let's start with what we had in the jar.

32, right?

And if I am going to take away 20, I can go back and I can say, subtract 10, subtract another 10 to be 20, right?

So if I do that, let's count backwards by 10s.

32, 22, 12.

And we come up with that same answer of 12 on our number line.

Great job, everybody!

Now, we said that there was two story problems.

So now, let's move on to our second story problem and this one has some cows involved.

So my friend, Riley, Ms. Riley has a farm and she has some cows on that farm.

And so she has 23 cows.

Can you believe that?

That's a lot of cows.

But guess what?

She's getting even more.

She was getting 30 more cows on her farm.

She's gonna be really busy taking care of all of those cows.

But she wants to know how many cows does she now have in total?

Well, if she started with 23, again, we could represent that number by drawing it out and saying two groups of 10, 10, 20, and then those three ones, right?

But now, we have to add in.

And we know we're adding because she's getting more, right?

So this time, we're adding.

And we say, we've gotta add 30 in there.

So three sets of 10 would make 30.

10, 20, 30.

Now, let's count up all of those and we would have five groups of 10.

So 10, 20, 30, 40, 50, plus those three and we've done it.

So now, if we do the number line, we could use that too and just count by tens, right?

And we said we had to add 30 on.

So 33, 43, 53.

Right?

It's the same thing.

We get to the same answer and we've done it.

So great problem solving today.

I know that was tough, but you guys did awesome.

So keep learning and keep problem solving.

And we'll be back again real soon.

(upbeat music)