PTCB test day
by Francesca
(USA)
On the PTCB test strategy page, it says:
"IMPORTANT  When you first sit down in front of the computer, before you hit the button to start the exam, write down as many conversions as you can remember on the dry erase board they provide."
Can you please provide examples of what exactly you suggest writing on the dry erase? What conversions did you write??? Thanks!
Reply (by Keith)
Good question. I actually wrote a little system I created for myself, which I simply named:
5 core conversions:
30mL = 1oz = 30gram
5mL = 1 tsp
15mL = 1 tbsp
1 pint = 16oz = 1 lb
1Kg = 2.2 lb
WHY?
Over time, I found that using these 5 I can do 90% of all conversions that I encountered. The conclusion I came to was that all the questions I could find to practice with all presented problems that were less than 1 lb or 1 gallon of compounding. The only exception is body weight, which is why Kg/lb is one of the five.
The reason these 5 work for me is because I can use them to maneuver around enough to tie everything together.
For example:
Syrup Z is dispensed in prepackaged 12oz bottles. You receive a drug order for: Rx: Syrup Z SIG: 2tsp QID X21D. How many 12oz. bottles will you dispense?
A. 1 (one) B. 2 (two) C. 3 (three) D. 4 (four)
This is a typical question and there are several ways to solve it. In my opinion, the easiest way to do it would be to sub in mL's for tsp's and then multiply across.
1. SIG: 2tsp QID X21D
So, we go to conversion #2. (5mL = 1tsp.) (Sub in conversion)
2(5mL)x(4)x(21) = 840mL
2. So, now we want to know how many oz. 840mL is:
So, we go to conversion #1 (30mL = 1oz)
840 Ã· 30 = 28
So, we need to dispense 28oz.
3. But, we have 12oz. bottles only.
28 Ã· 12 = 2.33
That means we need to dispense 3 bottles.

