About this video
A toy factory sells toys for $10 each and has 40 workers who each make 25 toys a day. The video multiplies $10 per toy by 40 workers times 25 toys per worker, cancelling units, to get $10,000 of toys per day. It also points out that the '5 days a week' fact is extra information not needed for a daily total.
You'll be able to
- multiply rates and use cancelling units to check my setup.
- find the total value of items produced in a day.
- spot extra information that a question doesn't need.
Key words
- rate
- A quantity per one unit of something else, like dollars per toy or toys per worker.
- units cancel
- When the same unit appears on the top and bottom of a multiplication, it divides out and disappears.
- extra information
- Facts in a word problem that aren't needed to answer the question asked.
Transcript
- [Narrator] We're told a factory makes toys that are sold for $10 apiece. The factory has 40 workers, and they each produce 25 toys a day. The factory is open five days a week. What is the total value of toys the factory produces in a day? Pause this video and see if you can figure that out.
All right, so let's just think about a day, before I even look at this information. If I could figure out the value per toy, and then multiply that times the number of toys, number of toys produced in a day, then we would have the total value. And let's see if they give us that information.
Well the value per toy, they say the toys are sold for $10 apiece, so we could write this this way. 10 dollars per toy, and then they do tell us, or they give us the information that we need to figure out how many are produced in a day. We have 40 workers, and they each produce 25 toys a day.
So the amount that's produced in a day, is going to be 40 workers times 25 toys per worker. Now I could say 25 toys per worker per day, and that makes the units a little complicated, or I could just realize that this entire expression I'm creating is talking about one day.
So the total number of toys produced in a day is going to be the product of these things. And we can say that the units work out, just to make sure that we're getting in the right direction. A toy in the denominator cancels out with the toys in the numerator, workers, when you multiply it, this would be in the numerator, this in the denominator.
So workers, workers cancel out. And so I'm gonna be left with 10 times 40 times 25 dollars. And I do want it written in dollars. And so this is going to be equal to 10 times 40 is 400, and then 400 times 25, let's see, that's going to be 4 times 25 times 100 so that's 100 times 100, which is 10,000, and then the units we're left with is dollars.
And now you might be saying, wait, we didn't use all of the information and that's true, we didn't use the fact that the factory is open 5 days a week. We didn't need to use that information. That would have been useful if they said, what is the total value of toys the factory produces in a week.
Then we would have said their value per day is $10,000, and we could even write it this way, per day, and then multiply that times 5 days in a week, and that would have given us the total value of the production in a week. But that's not what they're asking for, so we don't need that other information, and so we don't have to go to that step.
And so this is really just extra information, probably to distract you a bit.
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