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Calculate the following: 1.28 divided by four.
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In this question, we need to divide a decimal by an integer or a whole number.
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One method we could use is short division.
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We need to find out how many fours there are in 1.28.
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Now using short division like this is exactly the same method as when we divide two whole numbers.
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The only difference is we need to make sure our answer has a decimal point in it.
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Firstly, how many fours are in one?
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Well, the answer is zero.
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And we still have a remainder of one so we’ll cross through the one and write it next to the two.
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How many fours are in 12?
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We know three fours are 12 — four, eight, 12.
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And there’s no remainder, so we can just look at the last digit.
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How many fours in eight?
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There are two fours in eight.
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And so 1.28 divided by four equals 0.32 or 32 hundredths.
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That was a quick method.
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Let’s go through another strategy we could use that’s just as quick.
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This one involves partitioning.
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We can start by breaking up our decimal into the whole number and its decimal part.
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And so 1.28 is the same as one and 0.28.
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A good strategy for dividing by four is to halve, then halve again.
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Let’s use this strategy to divide our two parts by four.
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Half of one is 0.5.
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And half of 0.5 is the same as a quarter; it’s 0.25.
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So we know one divided by four equals 0.25.
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Now, let’s divide 0.28 using the same method.
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Half of 0.28 or 28 hundredths equals 14 hundredths or 0.14.
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And then half of 14 hundredths equals seven hundredths or 0.07.
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And so 0.28 divided by four equals 0.07.
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We’ve divided both parts of the number by four.
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Now, we just need to add our two answers together.
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Five hundredths and seven hundredths equals 12 hundredths.
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Two tenths plus zero tenths equals two tenths.
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But we’ve also exchanged to tenth that equals three tenths.
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And there’s nothing to add in the ones place.
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The answer is exactly the same as when we use short division.
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1.28 divided by four equals 0.32.