CONVERSION UNIT FACTOR Part One

WHAT DO WE MEAN BY UNIT? A unit tells us what we are talking about. It is a marker to “identify” something.

Examples:

5 dollars 3.5 pints 20 dimes3 cups 6 roses 18 ounces

a dozen eggs 10 shoes 3 pairs

CONVERSION UNIT FACTOR A conversion factor is a ratio of equivalent

values used to express the same quantity in different units.

12 eggs = 1 dozen2 shoes = 1 pair7 days = 1 week

Name the equivalent conversions you know that are used in the kitchen….

How many quarters are there in 3 Dollars ?

How many quarters are there in 3 Dollars ?

STEP 1: What units do we have? 3 dollars

STEP 2: What units are we looking for in our answer? quarters

STEP 3: What is our unit equivalency for dollars and quarters ?

4 quarters = 1 dollar4 quarters1 dollar

1 dollar4 quarters

3 Dollars has how many quarters?

STEP 4: Write out a multiplication problem starting with the units you have…

4 quarters = 1 dollar4 quarters1 dollar

1 dollar4 quarters

3 Dollars × 1 dollar

4 quarters WHY? You need the same unitOpposite to “cross multiply” and remove.

3 Dollars × 1 dollar

4 quarters

3 × 4 quarters = 12 quarters1 × 1 1 Answer: 12 quarters