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Units — Basic example

Watch Sal work through a basic Units problem.

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• this example was easy to understand and easy to learn
• Couldn't you just do 15*10 to get 150 and then choose the first one because if it is 3/4 then it will have to less than 150 and the only choice that is less than 150 is choice A
• There are more than one way to solve a problem. As long as the answer is right and you understand what you're doing, you should be fine.
• why do we keep the units when we know what our final units are
• Keeping the units is an easy way to see if you mix up the equation. For example, if you keep the units and end up with L/mg, you immediately know that you messed up, whereas without units, you might not catch that mistake.
• its easy just divide 10.3divided by 4 and multiply it by 15 you will get 112.5 you don't need to do complex math
• I multiplied 10 times 15 and then multiplied that by 0.75 and got the same answer. Is there any reason I shouldn't do it like that?
(1 vote)
• No, there isn't. In these sort of converting-between-unit problems, all you're doing is multiplying, so the order doesn't matter. You can find a standard order of doing the problem that works best for you: Maybe it's in order of what's given in the problem, or maybe you start at what's being asked for and work backwards form there. Who knows. But as long as you have all of the conversion factors you need, any order works.
• Could I have used the calculator to do the calculation?
(1 vote)
• So you convert the litters and milligrams?
• in a way yes i did it a different method so knowing that 1 liter = 10 mg , you'd just multiply 15 by 10 to get the amount in liter milligram or Lmg after that you multiply it by 3/4L causing you to just cancel the liters and making it milligrams :)
• So you convert the litters and milligrams?