Measurements and Calculations

• Its the quantitative observation/comparison 
• Contains two parts: A number and unit

A technique used to express very large or very small numbers based on powers of 10

Ex. 1.23 X 10²

The number before it is placed in scientific notation

• Symbol: K
• Value: 1,000
• SN: 10³

• Symbol: c
• Value: 0.01
• SN: 10^-2

• Symbol: m
• Value: 0.001
• SN: 10^-3

SI unit: Meter (m)

2.54cm (exact number)

SI unit: m³

SI unit: mL

1 cm³

The amount of 3-dimensional space in m³

• Amount of matter present 
• SI unit: kg

• A measurement always has some amount of uncertainty
• Comes from limitations of techniques & equipment

Can be used to indicate the uncertainty of a measurement.   

(0.57 ± 0.01)

• All nonzero integers are always significant 
• Leading zeros never count as SFs
• Captive zeros are always significant 
• Trailing zeros are significant if there is decimal pt

Exact numbers!

• ex. 2.54 cm/in
• 1000 mL in a L
• 121 students in a room

• Known with certainty 
• Defined numbers: 1 minute = 60 seconds ect