Med Math Question?

meanmaryjean, DNP, RN · May 15, 2018

Was it something along the lines of or was that the exact question? (Math is precise)

Why don't you show us what you think first- and then we can help you VS. just doing it for you.

nrsgstudnet1 · May 15, 2018

Hi,

As far as I remember (we aren't allowed to take the quizzes home), this was the exact question.

Here was my thought process:

Converted the 62.5 mcg to mg to get 0.0625 mg

Then I set up the formula to cross multiply 0.0625mg/x multiplied by 0.5mg/1mL

I got 0.5x = 0.0625

Divided 0.0625 by 0.5

My final answer = 0.125 mL

I know I don't use the same method as some do, but this is how it makes sense to me.

Thanks again!

bjwojcik · May 16, 2018

Hi Nrsgstudnet1,

The way you set it is is called ratio proportion. I prefer a method called dimensional analysis. You are starting with 62.5 mcg and have to change that mL of the 0.5 mg/mL solution. You don't have to pre-convert anything doing it this way. 62.5 mcg (1 mL/0.5 mg)(1 mg/1000 mcg) = 0.125 mL. If you learn this method, you can use it for unit conversions, dosage calculations, and IV Flow Rate Problems. You should take a lot at my article in the pre-nursing section: Master Your Drug Calculations Before You get to Nursing School. You will also find a helpful book there.

https://allnurses.com/pre-nursing-student/master-your-drug-1148937.html

nrsgstudnet1 · May 16, 2018

Thank you, the link is helpful!