(upbeat music) - Hey everybody it's Math Time once again and I'm so excited that you're here with me, because I've got a problem I need you to help me solve.

You see, I was playing with these building blocks earlier and I had these sets out and I was like you know what?

I wonder how many I have altogether.

But I knew, that I had four boxes with these different blocks inside, and every box had exactly 10 inside.

So I started thinking okay, I could count each one of these right?

And I could solve it that way but is there a more, I don't know efficient way is there another strategy we might use to solve this problem?

And I bet there is and I bet we can come up with one together so let's think through this.

Like I said we could talk through and draw this out and say all right, I know that I have a box right here, and I could count out little circles to represent all the building blocks inside.

So I could draw out 10 inside a box, and count those out and go one, two, three, four, five, six, seven, eight, nine, 10 right.

And I can do that four different times and keep counting on until I get to my number of whatever I have altogether.

But we could also think about this a little bit differently, 'cause let's think about it we know that there were four boxes right?

And each box had exactly 10 Legos inside.

So we could draw this out and kind of represent it visually like this.

And so I have these little number cubes to help me out, as I do this and each one of these has 10, right?

Well you could draw it on a piece of paper like that too and say, all right here's my 10 stick or little drawing that represents exactly 10 building blocks, and I can keep going through there now we know we had four boxes right?

So I can do this four times, and think, all right let's count by tens now we don't have to count by ones all the way up, we can count by tens, so I can go 10, I'll have another one I got to add 10 on so that's 20, add 10 more there's 30, add 10 more, there's 40, how many boxes is that?

That's one, two, three, four boxes and we've done it.

So how many building blocks that I have altogether?

Well there was 40, okay, and so that is another way we could solve it.

So yes we could count out each one individually, or we could use different representations to solve these problems, okay.

Now let's think about another scenario, this time I have 30 building blocks and they're just all spread out, okay.

So they're all over here and what I've got to do is I wanna put them in boxes, but I wanna put them in boxes where there's groups of 10 together.

How many boxes do I need if I start off with 30 total blocks?

All right, well we can think about the number 30 right?

And again we can draw this out and do it one by one, or we can think about how the number 30 is composed, what is it made of?

Well I know that that 30 can be broken down into groups of 10, right?

And so if I look at this I know that well 10, and then I could think of that's another 10, all right so another 10 would make 20, another 10 would make 30, and we're there, there's my 30 building blocks that I started with, now how many boxes do I need, to fill all those in and to have the right amount?

Well let's look back at our a little chart a little diagram here, where we had one, two, three different groups of 10, so I would need three boxes to do that right there okay.

And so three boxes of 10 is gonna equal 30 altogether.

Now here's the thing, we don't have to group things by tens all the time, sometimes we may wanna group by different numbers, let's take the same number of total building blocks, and let's say I have 30, but this time I want boxes of five, I only want five in a box, how many boxes am I gonna need?

Let's think through that.

Okay I can continue to break these tens apart I know, that 10 can be broken into two fives, so I can draw on from there and say all right five and five make a 10, another five and five make a 10.

And do that a third time for my third 10, and let's see how many boxes would I need if I only wanted groups of five.

Well if we go through there, let's count these up we have one, two, three, four, five and six, it would take six boxes to have only boxes with five blocks in each one, for all 30 of my blocks.

See there's lots of different ways that we can solve problems.

You may do it a little bit differently than somebody else, or depending on the problem, you may use a different strategy or a different way to solve things, and that's great.

We can draw things out just like we did early on we said hey you know what?

We can draw it out and represent with tens, we could use numbers we could use equations, see there's so many different ways, so keep learning, keep solving problems and I'll see you again real soon.

(upbeat music)