Math Quiz question

Sorry , but this doesn't make sense?

To figure a ratio you need two things:

1) the dose ordered (is that 50mg in this case?).

2) the concentration you have on hand (includes the volume).

For example, if you had a vial of a med that had a concentration of 100mg in 1ml (conc of med on hand including volume) and the dr order says to give 50mg (dose ordered) then you could figure the amount to draw up by:

if it is known that 100mg is in 1 ml, then how many [x] mls is 50 mg:

100mg 50mg

1ml = xml

then cross multiply:

100x = 50

then divide:

100 = 50

100 = 100 cancel out the cross 100's and divide 100 into 50:

=0.5ml

I think that some of the problem is missing. Or were they asking you to make up a concentration and show the math as above?

I hope you can read this. It's difficult to line up the fractions on the board!

Okay everyone...question..

On a calculation quiz today, question is express the labeled dose as a ratio. The dose was 50 mg in each 0.5 mL.

Apparently everyone in the class missed this for some reason. Any ideas?

Thanks!

100mg : 1ml ??

50 mg: 0.5 ml

Right? Isn't that how you express that as a ratio?

50 mg: 0.5 ml

That's what I thought at first and then I got to thinking that nothing is that easy in nursing school.

The whole example I used is ratios in medication math. I really wonder if the question is flawed or there is something missing?

See that is what I thought, makes no sense to me so no wonder we all missed it!

I just put 50:0.5 because I could not think of anything else. Unfortunatly, we only get our test scores back, no reiveiw, then the most missed problems are the ones on our quiz, so we never really get to find out what we did wrong until after the quiz! GRRRRRRRRR.

At least I am glad to know I am not crazy thinking something is not right here!

A ratio could also be written as a fraction. So, maybe 50mg/0.5mL ?? 50mg per 0.5 mL.