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- [Instructor] Let's[br]say we wanna figure out

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what eight divided by 4/10 is.

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Pause this video and try to[br]figure it out on your own

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before we do it together.

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All right, now one way to approach this is

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to think about everything[br]in terms of tenths.

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And why tenths, you ask?

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Well, I just described[br]the second number as 4/10.

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So what would eight be in terms of tenths?

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Well, we know that one whole

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is equal to 10/10,

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so eight wholes is going[br]to be equal to 80/10.

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So I could write that down over here.

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Instead of eight, I can[br]write that as 80/10.

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And I'm taking 80/10 and[br]I'm dividing that by,

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divided by 4/10.

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I'm just writing out, 4/10.

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So if I have 80 of something,

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and if I'm diving it into groups[br]of four of that something,

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how many equal groups am I going to have?

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Well, I'm gonna have 80[br]divided by four groups,

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or 80 divided by four,[br]eight divided by four.

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Actually, let me just write that down.

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This is going to be equal to 80 over four

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or 80 divided by four.

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And eight divided by four is two,

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so 80 divided by four is[br]going to be equal to 20.

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So eight divided by 4/10 is equal to 20.

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Another way that you[br]could think about that is

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to rewrite eight divided by 4/10

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as eight over 4/10.

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Over 4/10.

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And then if you wanted to rewrite this,

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you could say, "Hey, can[br]I multiply the numerator

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"and the denominator by some[br]quantity that'll get rid

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"of the decimal in the denominator?"

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Well, I could multiply[br]the denominator by 10.

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And if I don't wanna change[br]the value of the fraction,

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I have to multiply the[br]numerator by that same amount.

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Well, what does that get us?

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Well, this is going to be equal to,

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in the denominator right over here,

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I'm just going to have a four.

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So we got rid of the decimal.

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In the numerator, I am going to get 80.

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So once again, we get 80 over[br]four, which is equal to 20.

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Let's do another example,

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but in this case we'll[br]deal with hundredths.

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So let's say we want to figure out

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what is 48

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divided by 0.24

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or 24/100?

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Pause this video and[br]try to figure that out.

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All right, well, we can[br]do something very similar.

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This time we're dealing with hundredths,

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so we could try to express everything

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in terms of hundredths.

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So 48 is equal to how many hundredths?

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Well, we know that one[br]is equal to 100/100,

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so 48 is going to be equal

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to 48 times 100/100.

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Maybe I'll just write it like that.

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Or you might be able to[br]say, "Hey, that's 4,800

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"or 4,800/100."

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So let's just, actually,[br]I'll write it that way.

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This is going to be 4,800/100

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divided by, this is 24/100.

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24/100.

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And so what's that going to be?

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Well, same logic as we used up here.

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If I have 4,800 of something[br]or 4,800 of something

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and if I'm dividing it into equal groups

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of 24 of that something,

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well, I'm going to have 4,800[br]divided by 24 equal groups.

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So this is going to be equal to 4,800

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over 24.

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We could express 4,800 as, of[br]course, 48 times a hundred.

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So this is equal to 48

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times 100 over 24.

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And of course, you could[br]view this as the same thing

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as this is equal to 48 over 24.

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48 over 24, and many of you[br]might have already done it

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in your head, times 100.

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What's 48 divided by 24?

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Well, that is going to be equal to two.

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So two times a hundred is equal to 200.

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So this right over here is equal to 200.

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You can also do it in this type

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or do it similar to the way we did this

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where instead of[br]expressing it out as words,

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you could express it as 48 over 24/100.

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And instead of multiplying the numerator

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and denominator by 10,

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maybe you wanna multiply[br]it by something else

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to get whole numbers in both[br]the numerator and denominator.

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Think about that after this video,

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and try to work it out that way as well.