1. Significant Figures Non-zeros are significant.
Zeros between significant figures are significant.
Trailing zeros after the decimal point are significant.
Note: all measurements have some imprecision. Accurate counts can be perfect.

2. Significant Figures x=16.3cm means 16.25cm<x<16.35cm
When measuring, estimate an extra digit.
Using a meter stick (precise to nearest 0.001m), if the measurement appears to be on a mark, add a zero. If it appears to be between two marks, add a “5”.
Ex:
41.5cm
41.6 cm
41.65 cm
41.7 cm
41.70 cm

3. Multiplication & Division
Round to the number of significant figures that the original measurement with the fewest significant figures has.
43.6cm x cm = cm2
Final answer: 557 cm2
351m/1.756s = …m/s
Final answer: 2.00x102 m/s

4. Addition & Subtraction
Round to the decimal place of the least precise measurement.
12s s s = s
Final answer: 188s.

5. Unit Conversion Convert 15 mi/h to m/s. Convert 4.7 m3/min to L/h.
Multiply by a useful version of “1”
See inside of front cover and on p. 3
Convert 15 mi/h to m/s.
Convert 4.7 m3/min to L/h.

6. Read 6-10
HW: 7-26