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Sixty-two hundredths take away thirty-eight hundredths equals what?
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We know that we can subtract these fractions because they have the same denominator.
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Remember that the denominator or the bottom number in a fraction shows us the number of equal parts that the whole has been split into.
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So if we think of this square is representing one whole, a denominator of 100 means that our whole has been split into 100 equal parts.
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Each of these smaller squares is worth one hundredth.
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Remember also that the numerator or the top number in a fraction is the number of those parts that we’re dealing with.
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So for example, in the first fraction here, the numerator is 62.
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So our subtraction starts with sixty-two hundredths.
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As we’ve already mentioned, because the two denominators are the same, this means that we can subtract these two fractions easily.
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We start off with a number of hundreds and we subtract the smaller number of hundreds.
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So we know that our answer is going to be a number of hundredths, whatever’s left. the denominator in our answer then is going to be 100.
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What about the numerator?
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How many hundredths are we left with?
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Well, if we start with sixty-two hundredths and then subtract thirty-eight hundredths, the answer is going to be equivalent to 62 minus 38.
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What quick method could we use to find the answer to 62 minus 38?
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One mental method we could use to find the answer is to start with 62 and then to partition 38 into tens and ones.
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So subtract 30 and then subtract eight.
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Another method might be to start with 38 and to find the difference between 38 and 62.
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We could do this by counting on.
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A third method is to spot that the number 38 is very close to the number 40 and it’s easy to take away 40 from another number.
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This is an interesting and a quick strategy we can use.
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So let’s do that now.
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Start with 62.
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And because 38 is so close to 40, we’ll subtract 40 instead.
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62 take away 40 equals 22.
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Now although subtracting 40 was very quick, it’s not what we wanted to subtract.
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We wanted to subtract 38.
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So we’ve taken away two more than we needed to.
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So let’s add two onto our answer.
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22 plus two equals 24.
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So 62 take away 38 equals 24.
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And so, we’ve found our numerator, which is 24.
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Sixty-two hundredths take away thirty-eight hundredths leaves us with twenty-four hundredths.
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Interestingly, we could also use our knowledge of decimals to find the same answer, but express it in a different way.
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Sixty-two hundredths can be written as 0.62.
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And we can write thirty-eight hundredths as 0.38.
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Then, we can use our knowledge of subtracting 38 from 62 to help us subtract 0.38 from 0.62.
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The answer will be 0.24 or twenty-four hundredths.
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Both of these answers are equivalent.
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Use whichever method you’re most comfortable with.