Solving multiplication word problems
About this video
A pizza place makes 7 pizzas, each cut into 8 slices. The video draws the pizzas and shows that adding seven 8s is the same as multiplying 7 x 8 or 8 x 7. The total is 56 slices.
You'll be able to
- solve a word problem about equal groups using multiplication.
- explain that adding the same number many times is the same as multiplying.
- explain why 7 x 8 and 8 x 7 give the same total.
Key words
- multiply
- To find the total of equal groups quickly, like 7 groups of 8.
- equal groups
- Groups that each have the same number of things.
- total
- The amount you get when you put everything together.
Transcript
- [Instructor] We're told a pizza place makes seven pizzas. Each pizza is cut into eight slices. How many slices of pizza are there in total? Pause this video and try to figure that out. All right, now let's work through this together. So let's just imagine each of those pizzas, and each of them, we're gonna cut into eight slices.
And we have seven of them. So we could think about it like this. So if you can imagine, each circle here is one of those pizzas, and each of those pizzas are split into one, two, three, four, five, six, seven, eight slices, so, eight slices, and there's seven of those pizzas, one, two, three, four, five, six, seven.
So if you wanna know the total number of slices, you're essentially going to add these seven eights together. Well, adding seven eights is the same thing as multiplying eight by seven or seven by eight. Now, another way to think about it is you could think about each of those pizzas generating seven slices, or actually, each of those pizzas generating eight slices.
It was cut into eight slices, and there's seven pizzas. This is the first pizza, gets these eight slices, second pizza, these eight slices, all the way to the seventh pizza. Now, how many total slices there are? Well, again, we see we have seven rows of eight, so we would just add all of these eights together, which is again, the same thing as seven times eight or eight times seven, which if you were to add 'em all up, or you might already know, is equal to 56.
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