WEBVTT
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Calculate the following.
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27894 multiplied by three.
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In this question, we have a five-digit number.
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In this question, we have a five-digit number.
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This contains four ones, nine 10s, eight 100s, seven 1000s, and two 10s of 1000s.
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And we’re multiplying this number, which is 27894, by a single digit, three.
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And the calculation has been set out vertically like this for one reason.
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It’s so that we can use a type of written multiplication that helps us multiply each digit separately.
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We call this short multiplication because we’re only multiplying by a single digit.
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We can multiply each digit in turn.
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Let’s start off by looking at the ones.
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What are four ones multiplied by three?
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Well, we know four times three equals 12.
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So, the answer’s going to be 12 ones.
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12 ones are the same as two ones and one 10.
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Now, we can multiply the tens digit, which is nine.
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What is nine times three?
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We know that 10 times three is 30, so nine times three must be three less than 30.
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The answer is 27.
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Nine 10s times three is 27 10s.
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We already have one 10 underneath, so that’s 28 10s.
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We need to write 28.
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We’re gonna write the eight in the tens place and write our 20 10s as two 100s.
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Onto the hundreds digit.
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If we know that nine threes are 27, then eight threes must be another three less than 27.
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Eight threes are 24.
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So, eight 100s multiplied by three is 24 100s.
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We already have two 100s underneath.
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That takes us to 26 100s, which is the same as 2600.
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And if we look at our thousands digit, it’s gone down again.
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We said that eight threes were 24, so seven threes must be three less than 24.
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That’s 21.
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So, we can say seven 1000s multiplied by three are 21 1000s.
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We already have two 1000s underneath.
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That takes us to 23 1000s.
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And we write the three in the thousands place and our two, which represents 20 1000s, in the ten thousands place.
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Finally, two times three is six.
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So, two lots of 10000 times three are six lots of 10000.
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Plus the two underneath takes us to eight lots of 10000.
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The final thing we can do is to write our answer, using a comma to separate the thousands from the hundreds digits.
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This just makes it easier to read.
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This calculation was already written for us vertically, so we knew which method we were supposed to use.
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27894 multiplied by three equals 83682.