1. Understanding Significant Figures
Non Zero digits are always significant.
Zeroes are sometimes significant.
We can use these rules to decide whether or not they are significant

2. Significant Figures – When are zeroes significant?
Zeroes before a decimal point are significant
Zeroes between Non-zero digits are significant
Zeroes after non-zero digits without a decimal point or without another number after them are not significant
32000.
5 significant figures
32003
5 significant figures
32000
2 significant figures

3. Significant Figures – When are zeroes significant?
Zeroes after decimal point are significant in the following cases
When the zero is after a non-zero digits
When the zero is between non-zero digits
When the zeroes have no non-zero
digits with them
3 significant figures
4 significant figures
7 significant figures

4. Rounding to Significant Figures
We can follow the same rules when asking to round to a certain amount of significant figures Round the following answers to 2 significant figures =
= 3500 = =
= 240
= 4600

5. Rounding to Significant Figures
Round the following answers to 3 significant figures = = = =
= 293
= 4.31

6. Rounding to Significant Figures
How many significant figures have these numbers got? 3 4 5 1