1. FACTOR LABEL / PROBLEM SOLVING Chapter 4

2. Three step approach 1. Analyze a. What is known? b. What is unknown? c. Plan a solution strategy 2. Calculate 3. Evaluate a. Does my answer make sense?

3. Conversion Factors You should know these conversion factors: 1 gram = 1000 mg (milligrams) 1 gram = 100 cg (centigrams) 1000 gram = 1 kg (kilogram)

4. Dimensional Analysis (Factor Label) Problem solving method Example: How many miles is equal to 57.2 km? Conversion factors: ? miles = 57.2 km 0.621 mi = 1 km 57.2 km 1 km 0.621 mi = 35.5 mi ** Always start with the value equal to your unknown ** The next value should be your conversion factor ** The unit that you start with must be the unit on the bottom of the next conversion factor

5. Multi-step Problem How many years old is a person who is 350,500,000 seconds old? 350,500,000 sec 60 sec 1 min = 11.11 years 60 min 1 hr 24 hr 1 day 365 days 1 yr