Significant Figures are used to determine some level of accuracy within our recorded measurements.
Concept #1: Determining significant figures
Example #1: How many sig figs does each number contain?
0.0000185 m 749 mol
17.3 x 10^{3} mL 100. min
0.0010050 kg 1560 mol
Example #2: Read the length of the metal bar to the correct number of significant figures.
Concept #2: Understanding calculations with Significant Figures
The number of significant figures involved in a calculation depends on whether we are adding, subtracting, multiplying or dividing.
Example #3: Perform the following calculation to the right number of sig figs:
(3.16) x (0.003027) x (5.7 x 10^{-3})
Whenever we are adding or subtracting numbers with different exponents we must manipulate them to one common exponent value. We manipulate the values to get the least number of decimal places.
Example #4: Perform the following calculation to the right number of sig figs:
2.628 x 10^{6}
6.281 x 10^{4}
+ 0.827 x 10^{7}
Whenever we are dealing with a mixture of functions just remember your order of operations.
Example #5: Perform the following calculation to the right number of sig figs:
(42.00 – 40.915) • (25.739 – 25.729)
(11.50 • 1.001) + (0.00710 • 700.)