Imagine you have to take a measurement using the ruler shown below:
Figure 1. |
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Inches are marked in red. Centimeters are marked in blue. Millimeters are marked in green.
Here, our smallest unit of measurement is the millimeter. 1 Millimeter is our "Precision Unit"
When used correctly, the greatest possible error for this instument is half of its precision unit, or 1/2 of a Millimeter.
Figure 2. |
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Here, we've taken a measurement of 14.6cm. This measurement has three significant digits.
How do we count significant digits?
Counting Significant Digits |
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1. All nonzero digits are significant. 2. Zeros between significant digits are also significant. 3. Zeros used to show place values are not significant. 4. In numbers with a decimal point, all zeros to the right of a nonzero digit are significant. |
Below, we count the number of significant digits in four numbers:
Figure 3. |
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