Rules for significant figures

2. •In any measurement, the accurately knows digits and the
first doubtful digits are called significant figures?
•A significant figure is the one who is known to be reasonably
reliable
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3. • <7.4
• >7.5
• 7.42
• 7.43
• 7.44
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4. All the non-zero digits are significant
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5. All the zeros between the two non-zero digits are
significant , no matter where the decimal point is
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6. Zeros to the left of the significant figures are not
significant
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7. • Zeros to the right of the significant figures( trailing zeros ) are may or
may not be Significant.
• It depends upon the Measuring instrument ( Least Count ) of
measuring instrument
• E.g. 800 kg
• If the least count is 1 kg 800 kg all are confirmed
• If the least count is 10 kg 800 kg first two are confirmed
• If the least count is 100 kg 800 kg only first is confirmed
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9. • The powers of 10 are always non- significant.
• 23500 can be written as
• There are only three significant figures .
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