1. Significant Figures

2. A. Significant Figures
The more figures a number has, the more precise it is, right? 4 vs 4.56
What about 4 vs !?
Not all digits are meaningful contributions to the precision of a number
We distinguish between significant and insignificant figures of a number

3. Sigfigs Rules Rule 1: sigfigs are all numbers that are not zeros
22.3 has ____
3 sigfigs
has ____
1 sigfig
has ____
2 sigfigs

4. Rule 2: A zero can be a sigfig if
….it is between non-zeros sigfigs ….it is after the decimal point sigfigs 4.0 x sigfigs

5. Rule 3: A zero is not a sigfig if
1. It is before a number
00005 has ___
1 sigfig
2. Is at the end of large numbers
870,000 has ___
2 sigfigs

6. How many sigfigs do the following numbers have?
3.87
2,000,000
40078 4
40.00

7. In science, all reported figures of a result are considered significant
They not only represent the outcome of an experiment but also accuracy and precision of the equipment
Your worst equipment is the limiting factor for the sigfigs of the final result

8. Multistep experiments….
4.6 ml → K → atm = mg 2 sigfigs 4 sigfigs 6 sigfigs 5 sigfigs Result has to be rounded up to 2 sigfigs: 35 mg

9. Calculations in science
The number with the lowest sigfigs determines the sigfigs of the result!!!
Example:
10.555m x 2.3 sec= round to 24 m/sec
5sf sf sf sf

10. Practice
1.10 x 23.87=
0986 x 5.9 =
2.3 x =
a)26.3
b) 5,800
c) 23,000