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Write the answer in milliliters: 3.15 liters plus 6250 milliliters.
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When we see a question like this, it can be tempting to rush in and start the addition straight away.
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However, we should notice that we have two quantities that are given in different units.
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One is in liters and the other one is in milliliters.
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In order to add these, they’ll need to be in the same units.
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We could either change them both into liters or both into milliliters.
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But we’re asked to give the answer in milliliters, so it would be sensible to change them both into milliliters.
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We should recall that in one liter, there are 1000 milliliters.
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As we’re changing a quantity in liters into one in milliliters, we’ll therefore need to multiply by 1000.
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So 3.15 multiplied by 1000 will be 3150.
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When we’re multiplying by 1000, we move all of the digits three places to the left.
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Now that our two quantities are in the same units, we can add them.
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3150 plus 6250 gives us 9400.
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Therefore, we can give the answer in milliliters of 9400 milliliters.