2.  Have you ever been to a foreign country?  One of the most important things to do when visiting another country is to exchange currency.  For example, one United States dollar equals 1535.10 Lebanese Pounds.

3.  Whenever you exchange currency, you are utilizing the scientific method of dimensional analysis.

4.  Dimensional analysis is a problem-solving method that uses the idea that any number or expression can be multiplied by one without changing its value.  It is used to go from one unit to another.

5.  A conversion factor, or a fraction that is equal to one, is used, along with what you’re given, to determine what the new unit will be.

6.  What happens when you divide a number by itself?  What happens when you divide a unit by itself?  In both cases, you get the number 1.  Dimensional analysis involves multiplication and division.

8. 1. Start with the given value. 2. Write the multiplication symbol. 3. Choose the appropriate conversion factor. 4. The problem is solved by multiplying the given data & their units by the appropriate unit factors so that the desired units remain. 5. Remember, cancel like units.

9.  You can write any conversion as a fraction.  Be careful how you write that fraction.  For example, you can write 60 s = 1 min as 60s or 1 min 1 min 60 s

10.  To convert between units:  Figure out what CONVERSION FACTOR you need to perform your calculation  There are 12 inches in 1 foot  12 inches or 1 foot 1 foot 12 inches

11. 1. Suppose there are 12 slices of pizza in one pizza. How many slices are in 7 pizzas? Given: 7 pizzas Want: # of slices Conversion: 12 slices = one pizza

12. 7 pizzas 1  Check your work… X 12 slices 1 pizza = 84 slices

13. 2. How old are you in days? Given: 17 years Want: # of days Conversion: 365 days = one year

14.  Check your work… 17 years 1 X 365 days 1 year = 6052 days

15.  Most problems are not simple one-step solutions. Sometimes, you will have to perform multiple conversions.  Example: How old are you in hours? Given: 17 years Want: # of days Conversion #1: 365 days = one year Conversion #2: 24 hours = one day

16.  Check your work… 17 years 1 X 365 days 1 year X 24 hours 1 day = 148,920 hours

17. 1 foot = _____ inches 1 meter = _____ centimeters 1 pound = _______ ounces 1 minute = ______ seconds 1 hour = ________ minutes 12 100 16 60

18. Inches to feet Minutes to hours Meters to centimeters

19.  Dimensional Analysis can also be used for combination units.  Like converting km/h into cm/s.  Write the fraction in a “clean” manner: km/h becomes km h

20. › Kilo  So 1 km = 1000 m › Centi › So 100 cm = 1 m › Milli  So 1000 mm = 1m  Be able to use a chart for the others!