Problem 56P
Round the number on the left to the number of significant figures indicated by the example in the first row. (Use scientific notation as needed to avoid ambiguity.)
Number 
Rounded to 4 Significant Figures 
Rounded to 2 Significant Figures 
Rounded to 1 Significant Figures 
94.52118 
94.52 
95 
9 × 101 
105.4545 



0.455981 



0.009999991 



Solution 56P
Step 1:
First let’s see the rules for significant numbers :
 All nonzero digits are considered significant. For example, 81 has two significant figures 8 and 1, while 123.45 has five significant figures 1, 2, 3, 4 and 5.
 Zeros appearing anywhere between two nonzero digits are significant.
Example: 101.1203 has seven significant figures: 1, 0, 1, 1, 2, 0 and 3.
 Leading zeros are not significant. For example, 0.00052 has two significant figures: 5 and 2.
 Trailing zeros in a number containing a decimal point are significant. For example : 12.2300 has six significant figures: 1, 2, 2, 3, 0 and 0. The number 0.000122300 still has only six significant figures (the zeros before the 1 are not significant). In addition, 120.00 has five significant figures since it has three trailing zeros.