1. Pacific-Atlantic Method
Pacific-Present If the decimal is present, start counting from this side
Atlantic- Absent
If the decimal point is absent, start counting from this side
You are counting starting at the first nonzero digit you encounter and everything after that. This will give you the number of sig figs
100.0
6570
300000

2. Rules for Calculating with Sig Figs
Addition/Subtraction
Determine which number has the least number of digits to the RIGHT of the decimal point
That is how many numbers you can have to the right of the decimal point in your answer
Multiplication/Division
Your final answer will have the same number of sig figs as the measurement that has the smallest number of sig figs (least precise)
123 x
→ 658
x 2.14__ ?
97.3
→ 103.2
256.89 →
= 19
Rounded from 19.47
**Section review Qs: 1-4 pg 20
plus: how to do this with a calc