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Welcome to the presentation on dividing decimals.

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Let's get started with a problem.

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If I were to say how many times does 0.28 go into 23.828?

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So you're going to see that these dividing decimal problems

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are actually just like the level 4 division problems.

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You just have to figure out where to put the decimal.

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So what you do is you always want to take this decimal and

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move it over as many spaces as necessary to turn this

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number into a whole number.

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So in this case, we have to move it one space, two spaces

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over to put the decimal here.

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Well, if I did that with this number I have to do it

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with this number as well.

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So I moved it over two spaces to the right, so I have

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to move this decimal two spaces to the right-- 1, 2.

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Decimal goes here, and I put the decimal right

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above, right there.

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Now I can treat this 28 as a whole number.

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And if I want to, let me see if I could-- well, I want to erase

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the old decimal because if you were doing it with a pen you

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would kind of have the same problem I have.

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So now we do it just like a level 4 division problem.

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So we say, how many times does 28 go into 2?

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Well, no times.

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2 is smaller than 28.

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How many times does 28 go into 23?

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Once again, still, it goes into it zero times because

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23 is smaller than 28.

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How Many.

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Times does 28 go into 238?

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So let's think about that.

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28 is almost 30.

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238 is almost 240.

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So 30 goes into 240 eight times Because 3 goes

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into 24 eight times.

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So I'm going to guess that 28 goes into 238 eight times.

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And it literally it a guess.

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You have to try out some numbers sometimes.

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8 times 8 is 64.

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8 times 2 is 16.

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Plus 2 is 22.

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Subtract.

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I get 14.

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I guessed right because the remainder when I divide 28 into

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238 and I say it goes into it eight times is 14,

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which is less than 28.

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So 8 was the largest number of times that the 28 could go into

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238 without being larger.

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So now I bring down this 2.

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Once again, you recognize this is just purely a level 2

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division problem-- a level 4 division problem.

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So now I say, how many times does 28 go into 142?

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Well, once again, I'm going to approximate.

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28, it's almost 30.

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Let's see, 30 times 4 is 120.

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So yeah, I'll take a guess and I'll say let's say it

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goes into it four times.

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I could be wrong, but let's see if it works out.

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Let me get rid of this old 6.

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4 times 8 is 32.

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And 4 times 2 is 8.

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Plus 3 is 11.

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2 minus 2 is 0.

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4 minus 1 is 3.

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Huh.

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Interesting.

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So it turns out that my remainder here is larger than

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28, so I actually could have divided 28 into 142

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one more time.

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So let me go back and change that.

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See, it's not a mechanical thing.

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And if you feel unsure sometimes, you just have to try

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numbers and see if they work.

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And otherwise, you raise or lower the number accordingly.

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So let me erase that 4.

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I'm going to try not to mess up.

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Erase all this stuff down here.

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I probably should have tried it out on the side first before

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doing all this and I wouldn't have had to go back

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and erase it.

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And then let me get back to what I was doing.

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So when I went into it four times the remainder was too

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large, so let me try five now.

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5 times 8 is 40.

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5 times 2 is 10.

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Plus 4 is 14.

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142 minus 140 is 2.

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Good.

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2 is less than 28.

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This 5 is correct.

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Now I just bring down the 8.

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28 goes into 28 exactly one time.

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1 times 28 is 28.

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Remainder of 0.

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Done.

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So 28 goes into 2,382.8 85.1 times.

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Or you could say, 0.28 goes into 28.828 85.1 times.

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That's the answer we had gotten.

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And that makes sense.

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It's always good to do a reality check because if I took

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85.1 and I multiplied it by 0.28, it makes sense that

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I'd get a number around 23.

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0.28 is almost 1/3.

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So 23 is almost 1/3 of 85.

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So at least it makes sense in rough numbers.

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When you're doing decimals, if I had gotten 800 here instead

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of 85, I'd be like, oh, well, 0.28 times 800?

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I don't know if that equals 23.

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So it's always good to just do a reality check and get a sense

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for at least the magnitude of what your answer should be.

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Let's do another problem.

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Let's do 3.3 goes into 43.23.

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That's a 3.

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So first thing we want to do is move the decimal.

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We just have to move it one space here, so we move it

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once space here as well.

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Put the decimal right up here.

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And now it's just a level 4 division problem.

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33 goes into 4 zero times.

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33 goes into 43 one time.

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That's easy.

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1 times 33 is 33.

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Do the subtraction.

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43 minus 33 is 10.

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Bring down this 2.

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33 goes into 102?

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You could eyeball that one and say, about three times

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because 3 times 33 is 99.

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3 times 33 is 99.

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102 minus 99?

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Well, that's easy.

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That's 3.

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We just bring down this 3.

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33 goes into 33 one time.

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1 times 33 is 33.

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0.

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So 3.3 goes into 43.3 13.1 times.

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Or, if you move the decimal over, and when you move the

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decimal over to the right one spot, all you're doing is

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you're multiplying both the divisor and the dividend by 10.

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Which is fine as long as you multiply both of them by 10.

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It's also like saying 33 goes into 432.3 13.1 times.

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Let's do one more problem.

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I think I have time.

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YouTube puts a limit on this stuff.

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so let's say 2.5 goes into 0.3350 how many times?

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Well once again, let's move the decimal point over one here.

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So we move the decimal point over one here.

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Put the decimal here.

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So how many times does 25 go into 3?

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Well 0.

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So you could put a 0 here just for fun if you want.

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How many times does 25 go into 33?

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Well, it goes into it one time.

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1 times 25 is 25.

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33 minus 25 is 8.

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Bring down the five.

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25 goes into 85?

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Well, we know 25 times 3 is 75.

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So it'll go into it three times.

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3 times 25.

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We know that's 75.

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85 minus 75 is 10.

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Bring down the 0.

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Up here we had brought down the 5 before.

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And 25 goes into 100 four times.

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So our answer is 2.5 goes into 0.3350 0.134 times.

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So as you see, the only difference step between what

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we're doing when we're dividing decimals and when we're doing

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level 4 division is we just have to make sure we get the

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decimal in the right place.

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You shift the decimal here enough so that this becomes a

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whole number and you just have to shift the decimal here

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the same number of times.

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And once you do that it just becomes a level

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4 division problem.

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And the whole trick with level 4 division is always be willing

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to try numbers, and if the numbers don't work,

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adjust them accordingly.

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Don't feel that there should be a way that you can just always

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power through these problems.

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You have to do a little bit of trial and error and maybe use

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your eraser or do some work on side every now and then.

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But anyway, I think you're ready to do some dividing

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decimals problems.

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I hope you have some fun.