Solving multi-step problems (division): books
About this video
A bookstore receives 219 books and then 6 more, and puts them evenly on 3 shelves. The video adds first (219 + 6 = 225) and then uses long division to find 225 / 3 = 75 books on each shelf.
You'll be able to
- decide to add first and then divide in a two-step word problem.
- add a one-digit number to a three-digit number with regrouping.
- use long division to divide a three-digit number by a one-digit number.
Key words
- evenly
- Shared so that every group gets the same amount.
- long division
- A written way to divide big numbers one place at a time.
- remainder
- What is left over when a number can't be divided exactly.
Transcript
- [Instructor] A bookstore receives 219 new books and then gets six more as a last-minute delivery. The manager organizes all of the books evenly into three or onto three shelves. How many books are on each shelf? Pause this video and see if you can do this before we do this together.
All right, so what we wanna do is figure out the total number of books and then divide them evenly or divide them by three. And so the total number of books is going to be 219. I'm gonna try to keep the colors the same, 219 books, and then they get 6 more. So this is the total number of books.
So we're going to want to calculate that first. And then we wanna divide that evenly into three shelves. So we could just divide that by three, divide by three. So what's 219 plus 6? So what we could do is, well, we might be able to do that in our head. What's 19 plus 6?
Well, 19 plus 1 is 20, and then you have 5 left, so it's gonna be 25. So 219 plus 6 is 225. So this is 225. Just to make that clear, let me do this here, 219 plus 6, 9 plus 6 is 15. My brain is doing the wrong thing. Regroup that one, and then we just have tens here.
So we have one 10 plus another 10 is two 10s, and then we have the two hundreds. But you might've just said, "Okay, 19 plus 6 is going to be 25. "So 219 plus 6 is 225." And then we wanna divide that by 3, so we could do a little bit of long division now. So if we say, how many times does 3 go into 225?
Well, we could see 3 doesn't go into 2, but it does go into 22 seven times, 7 times 3 is 21, we can subtract, 22 minus 21 is one, bring down this 5, we get a 15. 3 goes into 15 exactly five times, 5 times three is 15, and then we have no remainder. So 225 divided by 3 is 75.
So we have exactly 75 books on each shelf, and we're done.
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