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 kg = 1000 g
Because we are converting from grams to kilograms, “1 kg” goes on top. 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 top. 1 kg = 1000 g
Step 5 Multiply the two fractions, making sure to cancel like units. 1 kg 5195 kg 5195 g = X 1 1000 1000 g
Step 6 Complete the mathematical operation and then circle your answer. 1 kg 5195 kg 5195 g 5.195 kg = X = 1 1000 1000 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 m = 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 m = 1 km
Step 5 Multiply the two fractions, making sure to cancel like units. 1000 m 2400 m 2.4 km = X 1 1 1 km
Step 6 Complete the mathematical operation and then circle your answer. 1000 m 2400 m 2.4 km 2400 m = X = 1 1 1 km