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Hi there.
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Each of these three questions involves calculations using measurements.
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So whenever we're working with calculations using measurements, we have to round our answer to the correct number of significant figures based upon the rules for significant figures.
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And we'll talk about these rules as we do each problem.
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So let's start with number seven.
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Number seven, we are adding 6 .32 milliliters of water to.
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A cylinder that already contains 25 .0 milliliters.
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So first thing we want to do is just add these two numbers together.
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This gives us 31 .32 milliliters.
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However, now we need to round the correct number of significant figures.
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Whenever we are adding or subtracting, we round to the position of the number that has the fewest decimal places.
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Or if there are no decimal places, we look for the position of the uncertain digit in the least precise number.
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Well, as we're looking at these, we see that 6 .32 has two decimal places.
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25 .0 only has one.
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That means we need to round to just one decimal place.
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Making our final answer, 31 .3 millimeters.
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All right, so final answer, 31 .3 millimeters.
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Since the next digit was 2, we did not round up.
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Okay, let's look at number 8.
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Number 8, we're trying to calculate a volume.
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And we have a box, so to calculate the volume of a box, we need to take length times width times height.
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And it doesn't matter which measurement is considered the length or the width of the height, as long as we're multiplying the three together...