(upbeat music) - Hey everybody, just here looking through some of my old sports cards.

I used to love collecting these and looking through them.

I would read the backs of them.

They would have these stories or statistics to tell you about each player.

I had cards for basketball players and baseball and football players and, of course, some Michael Jordan cards because he is the GOAT, the greatest of all time, MJ 23 and that actually leads into our story problem of today for our math lesson.

Let's imagine that we have a collection of sports cards and there are 10 cards per page, on each one of these pages that we have.

So 10 cards on every page and in each binder, we have 10 pages of cards.

Now all together we have nine binders, so how many cards will there be?

Whew.

Okay, this is a complicated problem.

Did you catch all of that information?

Let's try and break down the problem so that we can really even understand it.

Then we can try and solve that last question of how many cards there are all together because anytime there's a problem, we've got to really focus on the information we already know before we try and answer that question that we don't know yet.

So let's go through the information we do know one more time.

Okay, we know that there are 10 cards on every one of these pages.

Okay, check.

We also know that there are 10 pages in each binder, right?

Okay, we got that one.

And we know that there are nine binders all together that have cards in them.

Okay, that is still a lot of information to try and process, but before we try and figure it out, how many cards there are in total, let's focus on can we figure out how many cards are in just one binder?

Maybe that'll help us out and you know what we can use, our handy dandy chalkboard.

Chalkboard board.

(Joel claps) (chalkboard sliding) Here we go.

Now we're ready and in fact, let's look at a couple of different strategies that we might use to figure this out.

Let's look at strategy number one.

Okay, now let's see if we can, just by looking at the information that this student has worked on and they've done, can we figure out what they were thinking?

So we can see that there's a box here that has circles in it and each circle has 10 written inside.

What do you think those represent?

Well the 10 is probably, do you remember, there were 10 cards on every page, right, so I think this student wrote a circle with the 10 in it to represent the 10 cards for each page.

Now they're trying to figure out how many cards are in just one binder.

So how many pages were in a binder?

Well, there was 10 of them.

So we can see that they drew 10 circles, right?

So we have 10 circles inside of our box, which is representing those 10 pages of 10 cards in one binder.

So now we can add up all of those 10s, right?

So 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 cards just in one binder.

Okay, that's good, right?

That's a great start because now we know how many cards are in one binder, but the next question was how many cards are there all together?

Well do you remember how many binders there are?

There were nine.

So now that we know there was 100 cards, look at what the strategy is showing us.

They added these together by a hundred 'cause they know that there's a hundred cards in every binder so 100 plus 100 would be our second binder and we're up to 200.

Now we add 100 more and we're up to 300 and that's our third binder and we can keep adding 100 until we get to all nine binders and once we're there, we can figure out our total, which they're saying is 900 cards.

It's a lot of cards and that's a great solving strategy there.

Let's look at one more strategy.

Our second strategy, this student did it a little bit differently, okay?

They started off with, hey, I know that there are 10 groups of 10, right?

That's what that multiplication sign is really showing us.

It's groups of.

So what are the 10 groups of 10?

Well, it's the 10 cards grouped into all those 10 pages, right?

And 10 groups of 10 they knew, hey, that's 100 and so now that they already know that, they can draw them out and they're saying, well, there were nine binders, so 100, 200, 300, 400 and they're doing that total as they go until they get to their nine binders and look at that answer.

It's the same thing.

It's 900 cards, which is what our first solution strategy also got.

So there are multiple ways of solving problems and this was a complicated one.

Thanks for persevering with me.

We've got to make sure we don't give up on problems and we continue to try and find solutions and sometimes it's hard and sometimes we might make mistakes, but that's okay.

We got to keep working and keep trying to solve those problems.

Thanks for joining us today.

(upbeat music)