Hello!
Here are some rules to determine the number of significant figures.
- Numbers that are not zero are significant (45 - all are sigfigs)
- Zeros between non-zero digits are significant (3006 → all are sigfigs)
- Trailing zeros are not significant (0.067 → the first two zeros are not sigfigs)
- Trailing zeros after a decimal point are always significant (1.000 → all are sigfigs)
- Trailing zeros in a whole number are not significant (7800 → the last two zeros are not sigfigs)
- In scientific notation, the exponential digits are not significant, known as place holders (6.02 x 10² → 10² is not a sigfig)
Now, let's find the number of significant figures in each given number.
A). 296.54
Since these digits are all <em>non-zero</em>, there are 5 significant figures.
B). 5003.1
Since the two <em>zeros are between non-zero digits</em>, they are significant figures. Thus, there are 5 significant figures.
C). 360.01
Again, the two zeros are between non-zero digits. There are 5 significant figures.
D). 18.3
All of these digits are non-zero, hence, there are 3 significant figures.
Therefore, expression D has the fewest number of significant figures being 3.
