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Factor-Label Method (of conversion). The factor-label method was developed to keep track of units in multi-step conversion problems. Factor-label method is a method for solving problems.
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The factor-label method was developed to keep track of units in multi-step conversion problems
Factor-label method is a method for solving problems. • It is a neat and organized method that can be used in science, math, shopping, building, cooking and many other situations.
In life you will need to be able to switch back and forth between different units. • For example- a video may be listed as 101 minutes long. You want to know how long the movie is in hours, to find out you need to do a factor label problem.
To solve this problem we are going to learn a generic set-up and use it to solve EVERY problem for the rest of the year. What you = what you know x the fractions you want to find need to get your answer
For our video problem… • What you want to find = hours • What you know = the movie is 101 minutes • The fractions you need= 1 hour = 60 minutes
The set up would look like… # hours = 101 min x = 1 hour 60 min 1.68 hours
Make sure… • Units cancel out----- • This means what ever you start with is ‘on top’ and you alternate units top and bottom so they cancel out. A B C D A B C X X X = D
Make sure… • You box your answer. • I won’t know what your answer is if I cannot find it!
Lets try another one! • Many of the problems will involve more than one step, so lets take the video problem a little further. • The video is 101 minutes long, how many days long is it?
What we want to find = days • What we know = the movie is 101 minutes • Fractions we need = 1 hour = 60 minutes • 1 day = 24 hours
# days = 101 min 1 hour 1 day 60 min 24 hr X X = 0.0701 days
If I am driving 2 km/sec how fast am I going in miles / hour? 2 Km 1000 m 1 mi 60 sec 60 min 1 sec 1 Km 1600 m 1min 1 hr X X X X = 4500 mph