Use dimensional analysis. Start with what you are looking for. (ml)
ml=
You know the morphine is supplied in gr 1/4 per ml. (when writing this out on paper, put the division as a line directly below the first number and the second number underneath.)
ml= 1ml/gr1/4
You are given that gr 1 is equal to 60mg.
ml=1ml/gr1/4*gr1/60mg
And the ordered dose is 2mg.
ml=1ml/gr1/4*gr1/60mg*2mg
You now multiply straight across.
On top: 1ml * gr1 * 2mg= 2 (no label yet)
--------------------------------------------
On bottom: gr1/4 * 60mg = 15 (no label yet)
So now you have
ml=2/15
which is equal to 0.13 (with 3 unendlessly, but for this purpose round to 0.13)
Now to check youself, be sure that all of the labels cross each other out except for the one you are looking for. (ie, is there a grain label on both top and bottom? ml label on both top and bottom?) This only leaves the ml which is what the original problem asks for.
Hope this helps!!!
Jessi
:luck: