SL#14 How to use Conversion Factors (a.k.a. Dimensional Analysis)

SL#14 How to use Conversion Factors (a.k.a. Dimensional Analysis)

Problem: 5,195 g equals how many kilograms?

Step 1 Write down the starting value with its units. 5195 g

Step 2 Make a fraction out of this number by putting it over 1. 5195 g 1

Step 3 Find an equivalency that has both the unit you are starting with and the unit you want to convert to. 5195 g 1 1 1000

Step 4 Turn your equivalency into a fraction by putting the number with the unit you are converting to on top. 5195 g 1 Because we are converting from grams to kilograms, “1 kg” goes on 1 top. 1000

Step 5 Multiply the two fractions, making sure to cancel like units. 5195 g 1 X 1 kg 1000 g 5195 kg 1000

Step 6 Complete the mathematical operation and then circle your answer. 5195 g 1 1 5195 X 5.195 kg kg 1000 1000 kg g

You have just calculated that 5,195 g equals 5.195 kg! Way to go!

Another Example 2.4 kilometers equals how many meters? Note: 1 km 1000 m

Step 1 Write down the starting value with its units. 2.4 km

Step 2 Make a fraction out of this number by putting it over 1. 2.4 km 1

Step 3 Find an equivalency that has your starting unit and your finishing unit. 2.4 km 1 1000 1 km

Step 4 Turn your equivalency into a fraction by putting the number with the unit you are converting to on top. 2.4 km 1 1000 1 km

Step 5 Multiply the two fractions, making sure to cancel like units. 2.4 km 1 1000 X m 1 km 2400 m 1

Step 6 Complete the mathematical operation and then circle your answer. 2.4 km 1 1000 2400 m X m 2400 m 1 1 km