Giga (G)

Meaning: 1,000,000,000
Order of Magnitude:

Mega (M)

Meaning: 1,000,000
Order of Magnitude:

Kilo (k)

Meaning: 1,000
Order of Magnitude:

Hecto (h)

Meaning: 100
Order of Magnitude:

Deka (da)

Meaning: 10
Order of Magnitude:

Deci (d)

Meaning: 0.1
Order of Magnitude:

Centi (c)

Meaning: 0.01
Order of Magnitude:

Milli (m)

Meaning: 0.001
Order of Magnitude:

Micro (µ)

Meaning: 0.000001
Order of Magnitude:

Nano (n)

Meaning: 0.000000001
Order of Magnitude:

Temperature Conversion Formulas

Celsius to Kelvin

What is the formula to convert Celsius to Kelvin?

Kelvin to Celsius

What is the formula to convert Kelvin to Celsius?

Fahrenheit to Celsius

What is the formula to convert Fahrenheit to Celsius?

Celsius to Fahrenheit

What is the formula to convert Celsius to Fahrenheit?

Fahrenheit to Kelvin

What is the formula to convert Fahrenheit to Kelvin?

Kelvin to Fahrenheit

What is the formula to convert Kelvin to Fahrenheit?

The Seven Base SI Units

Length

What is the base SI unit for length?
Meter (m)

Mass

What is the base SI unit for mass?
Kilogram (kg)

Time

What is the base SI unit for time?
Second (s)

Amount of Substance

What is the base SI unit for the amount of substance?
Mole (mol)

Temperature

What is the base SI unit for temperature?
Kelvin (K)

Electric Current

What is the base SI unit for electric current?
Ampere (amp)

Luminous Intensity

What is the base SI unit for luminous intensity?
Candela (cd)

Significant Figures (SigFigs) Practice

Concept

Significant figures indicate the precision of a measured value.

Rules for Determining Significant Figures

Non-zero digits are always significant.
Example: 123 has 3 sigfigs.
Any zeros between non-zero digits are significant.
Example: 1002 has 4 sigfigs.
Leading zeros (zeros before non-zero digits) are not significant.
Example: 0.0025 has 2 sigfigs.
Trailing zeros in a decimal number are significant.
Example: 0.500 has 3 sigfigs.
Trailing zeros in a whole number without a decimal point are ambiguous and typically not considered significant unless specified.
Example: 1000 has 1 sigfig, but 1000. has 4 sigfigs.

Examples

How many significant figures does 0.00789 have?
3 significant figures.
How many significant figures does 5.030 have?
4 significant figures.
How many significant figures does 300 have?
Ambiguous. Could be 1, 2, or 3 depending on notation.
How many significant figures does 300.0 have?
4 significant figures.

Practice Problems

Determine the number of significant figures in the following:
0.00456
70.0
10001
0.0001
Perform the following calculations with the correct number of significant figures:
Answers:
1.
3 sigfigs
3 sigfigs
5 sigfigs
1 sigfig
(2 sigfigs)
(2 sigfigs)
(3 sigfigs)

Unit Conversions

Concept

Unit conversions are used to express a quantity in different units without changing its value.

Common Conversions

Length:
1 meter = 100 centimeters
1 kilometer = 1,000 meters
1 inch = 2.54 centimeters
1 mile = 1,609 meters
Mass:
1 kilogram = 1,000 grams
1 gram = 1,000 milligrams
1 pound = 0.453592 kilograms
Time:
1 hour = 60 minutes
1 minute = 60 seconds
Volume:
1 liter = 1,000 milliliters
1 gallon = 3.78541 liters
1 cubic meter = 1,000 liters
Energy:
1 joule = 0.239005 calories
1 kilowatt-hour = 3.6 million joules

Practice Problems

Convert the following:
5 kilometers to meters.
12 inches to centimeters.
3 gallons to liters.
450 grams to kilograms.
Answers:
1.
5 kilometers = 5,000 meters
12 inches = 30.48 centimeters
3 gallons = 11.35623 liters
450 grams = 0.45 kilograms