Sig Figs Calculations Examples

Answer explanation

Addition and Subtraction Rules: The final answer cannot have an uncertainty that is smaller than the uncertainty of any of the parts. The parts have uncertainties 0.001, 0.1, and 0.01 (minimum).

Answer explanation

Multiplication and Division rules: 0.0301 and 2.31 both contain 3 sig figs

Answer explanation

Be careful to follow order of operations; each computation generates a value with a given certainty that is carried to the next calculation. Here, you have 2.5110*21.20/(45.333), where the denominator is uncertain in the hundredths digit (0.01 minimum error). All values then have at least four sig figs.

Answer explanation

Order of Operations: The product has only one sig fig due to the value 0.3; the sum then becomes 3.603 + 4.811, where the first value has an uncertainty of at least 1. Thus the final answer is 8.414 with an uncertainty of 1 (minimum), or simply 8.

The width, length, and height of a small box are 15.5 cm, 27.3 cm, and 5.4 cm, relatively. Calculate the volume of the box, using the correct number of significant figures in your answer.

Answer explanation

V = L*w*h, 5.4 cm has two sig figs

A balance has a precision of ± 0.001 g. A sample that has a mass of about 25 g is placed on this balance. How many significant figures should be reported for this measurement?

Hint: Start by considering the value you would write.

Answer explanation

The value would be 25.000 g or a similar value (e.g. 25.001 g). The precision of an instrument tells the last significant digit in any measurement.

Do you understand how to apply sig figs in calculations?

• Completely

• I understand the multiplication and division rules only

• I understand the addition and subtraction rules only

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• I do not understand sig figs