About this video
Sal divides 3,771 by 8 using long division. He explains that '8 goes into 37 four times' really means 8 goes into 3,700 four hundred times, then continues with 57 and 11 to get 471 remainder 3.
You'll be able to
- divide a four-digit number by a one-digit number using long division.
- explain what each step means in terms of place value.
- find the remainder at the end of a long division.
Key words
- long division
- A step-by-step written method for dividing, one place value at a time.
- remainder
- What is left over when the divisor doesn't go in exactly.
- place value
- The value of a digit based on its position, such as hundreds or tens.
Transcript
Let's divide 3,771 by 8. So we're going to do a little bit of long division is the way we set it up. So the first thing we want to do and think about is, well, does 8 go into 3? Well, no, 8 does not go into 3. So we'll keep moving. Does 8 go into 37? Sure. 8 times 4 is 37.
8 times 5 is 40. So that's too big. So 8 goes into 37 four times. 4 times 8 is 32. And we subtract, and we get 37 minus 32 is 5. And just so you have a little glimpse of what's actually going on here, we're really saying how many times does 8 go into 3,700? And we're saying that 8 goes into 3,700 400 times.
There's 4 sitting in the hundreds place, and that 400 times 8 is 3,200. And then when you subtract 3,200 from 3,700, you're getting 500. But we'll revert back to just the traditional long division mechanics. But that's what's really going on here. When we say 8 goes into 37 four times, we're really saying 8 goes into 3,700 400 times.
But let's keep going. So now, we have this 5 to deal with, which is, as we already talked about, it's in the hundreds place. It's really a 500. But now, let's bring down another place value. So let's bring down the 7. And let's think about how many times does 8 go into 57.
And we're really thinking about how much 8 goes into 570. But 8 goes into 57-- let's see, 8 times 5 is 40. 8 times 6 is 48. 8 times 7 is 54. So let's go 7 times. 7 times 8. Oh, actually, I did that right. 8 times 7-- my multiplication tables are weak. It is 8 times-- so it does go in seven times.
But 7 times 8 isn't 54; it's 56. I always have trouble with that one. It is 56. And so now, we subtract again. And 57 minus 56 is 1. And now we have one more place value to bring down. We have-- let me do it in in a color I haven't used yet. I'll do blue. We have a 1 to bring down.
And now we're literally saying, how many times does 8 go into 11? Well, 8 goes into 11 one time. 1 times 8 is 8. And we are left with-- because we have no more places to bring down-- 11 minus 8 is 3. So 8 goes into 3,771 471 times, and the remainder here is 3.
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