Significant figures are necessary to communicate the level of accuracy with which values are recorded. 

Significant Figures

Concept #1: To determine the number of significant figures for a value is dependent on the presence of a demical point. 

Example #1: How many sig figs does each number contain?

(1) 0.0001010 m                (2) 10034 s                                             

 

(3) 2.00 x 103 m                  (4) 15010 L

● Multiplication/Division: Measurement with least SIG FIGS determines final answer.

● Addition/Subtraction: Measurement with least DECIMAL PLACES determines final answer.

Example #2: Perform the following calculations to the right number of sig figs:

[(0.999 + 1.01) ● (15.1 - 0.815)] / (0.010)(16) + (33.3 + 7.5) 

Example #3: Read the water level with the correct number of significant figures. 

 

A) 20 mL      B) 20.0 mL      C) 20.2 mL      D) 20.00 mL      E) 20.20 mL

Practice: Read the ruler measurement to the correct number of significant figures.

Practice: Read the ruler measurement to the correct number of significant figures.