FACTOR LABEL METHOD

In math you use numbers, in chemistry we use quantities. In math you use numbers, in chemistry we use quantities. A quantity is described by a number and a unit. A quantity is described by a number and a unit. 100 is a number : 100 Kg is a quantity 100 is a number : 100 Kg is a quantity

Sometimes You Have to Convert Between Different Units How many seconds are in a day? How many seconds are in a day? How many inches are in a centimeter? How many inches are in a centimeter? If you are going 50 miles per hour, If you are going 50 miles per hour, how many meters per second are you how many meters per second are you traveling? traveling? To answer these questions you need To answer these questions you need to change (convert) from one unit to to change (convert) from one unit to another. another.

what is dimensional analysis? The converting from one unit system to another. The converting from one unit system to another. If this is all that it is, why make such a fuss about it? Very simple. Wrong units lead to wrong answers. Scientists have If this is all that it is, why make such a fuss about it? Very simple. Wrong units lead to wrong answers. Scientists have thus evolved an entire system of unit conversion. thus evolved an entire system of unit conversion.

How does it work? It will involve some easy math (Multiplication & Division) It will involve some easy math (Multiplication & Division) to perform any conversion, you need a conversion factor. to perform any conversion, you need a conversion factor. Conversion factors are made from any two termsConversion factors are made from any two terms that describe the same or equivalent “amounts” of what we are interested in. For example, we know that: For example, we know that: 1 inch = 2.54 centimeters 1 inch = 2.54 centimeters 1 dozen = 12 1 dozen = 12

3.5 miles = ________m 3.5 miles = ________m

3 m= ______in 3 m= ______in

350 g = _____ lbs 350 g = _____ lbs

6 gal= _____ fl oz 6 gal= _____ fl oz (1 gal = 4qts) (1 qt = __fl oz) (1 gal = 4qts) (1 qt = __fl oz)

7 days =_______seconds 7 days =_______seconds

. How many basketballs can be carried by 8 buses? · 1 bus = 12 cars · 3 cars = 1 truck · 1000 basketballs = 1 truck · 1 bus = 12 cars · 3 cars = 1 truck · 1000 basketballs = 1 truck

30 oranges = ______pineapples 1 pear = 2 melons 1 pear = 2 melons 2 pineapples= 3 melons 2 pineapples= 3 melons 5 pears= 4 oranges 5 pears= 4 oranges

PRACTICE 2. How many grams in 150 pounds given the equalities 2. How many grams in 150 pounds given the equalities 1 pound = kg and 1 kg = 1000 grams?

1.How many yards = 50 meters? (HINT: yards…feet…meters) 2. How many seconds are in 15 hours? 3. How many ounces are in 3.27 tons if (1 ton = 2000 pounds) & (16 oz = 1 lb) 4.Convert 399,338 inches to miles. (5280 feet = 1 mi)

kiloliters convert to mL? 6.How many seconds are in 17 days? 7. How many ML are in 3.5 gallons? (4 quarts = 1 gal) miles = ____km

9. Convert 9 gal to ML 10. Convert 12 meters to feet