PTCB test day

by Francesca

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!


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


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 pre-packaged 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.

SIG: 2tsp QID X21D

So, we go to conversion #2. (5mL = 1tsp.)
(Sub in conversion)

2(5mL)x(4)x(21) = 840mL

So, now we want to know how many oz. 840mL is:

So, we go to conversion #1 (30mL = 1oz)

840 ÷ 30 = 28

So, we need to dispense 28oz.

But, we have 12oz. bottles only.

28 ÷ 12 = 2.33

That means we need to dispense 3 bottles.

Comments for
PTCB test day

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Feb 28, 2012
More thoughts
by: Keith

Keep in mind that the reason I recommend writing them down is also to get them off your mind and on to paper. During the test, your mind will be racing with other information. So, if you can just glance at your conversions when you need them, that's one less thing to deal with. So, anything you want to write down to work from after you sit down will help you and keep you organized. It's not cheating either, since you pulled it from your brain. You do have to show them everything you wrote down, but the test proctors don't care about that stuff. Good Luck !

Feb 29, 2012
Cramming for the PTCB
by: Francesca

Awesome!!! Thanks Keith, you have no idea how much this helps. Your site has already streamlined my studies in such a way that I feel more and more confident as each day passes. Math is my weak spot but you give me hope that I can get through enough to the point to at least eliminate some wrong answers; therefore, increasing my odds at picking the correct answer. My only regret is that I stumbled upon your site within 5 weeks of having to take the exam. I wish I found it much sooner because it clarifies so many topics that once felt so above my head. Thank goodness I Googled "Cramming for the PTCB exam"...because it leads to you! : )

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