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Unformatted text preview: measurements to determine the precision of the result. The following is a shortcut that can be used when exact results are not crucial. Multiplication and division, count the number of significant figures . The result is expressed with the same number of digits as the least precise of the measurements. e.g. The density of a compound with a mass of 12.4 g (three SF) and a volume of 13 mL (two SF): = 12.4 g/ 13 ml = 0.95 g/ml (two SF) b) Addition and subtraction, the result contains the same precision as the least precise measurement: e.g. the result of adding the masses obtained in balances with different precision: 9.9 g + 10.128 g + 10.1305 g = 30.2 g (tenths of a gram). Round off the each of the following numbers to three SF: 2.23456 223456 2.23600 223600 2.23556 223556 2.24556 224556 Note: 5 rounds to the nearest even number 1.75 2SF rounds 1.8 and 1.25 rounds to 1.2...
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- Summer '10