Dose calculations in FA (b/c I'm a dumbass)

Discussion in 'Step I' started by Taus, Mar 23, 2007.

1. Taus.Moderator 10+ Year Member

3,801
380
Feb 1, 2005
Philly
OK..I'm a dumbass and have a pretty basic question..

On page 210 they have the formula for calculating loading dose as: Cp x Vd / f

Is it (Cp x Vd) / f or Cp x (Vd/f) ?

I remember the "PEMDAS" mnemonic from highschool and think its the first way w/ multiplying first....but I'd appreciate if someone could chime in on this.

3. surprisedgirl 2+ Year Member

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Oct 11, 2006
i believe its the first

4. domer621MS4 5+ Year Member

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Jul 24, 2004
surprisedgirl is correct.

5. Taus.Moderator 10+ Year Member

3,801
380
Feb 1, 2005
Philly
hmm...taking a look at some practice questions Qbook has it the 2nd way and Katzung in the Lange Qbook has it the first way....wtf...

6. surprisedgirl 2+ Year Member

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Oct 11, 2006
i havent studied that stuff nor have i looke dat it since last year but im pretty sure thats how i remember it.....and that seems right anyway

7. mountainman123Guest

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Jul 18, 2006
Yeah I remember trying to figure that out and they both give the same answer if you plug in fake numbers and solve (I think...... too lazy to do it right now)

5,818
144
Jul 12, 2003
GMT+9
Either

3,801
380
Feb 1, 2005
Philly
thanks

396
0
Mar 31, 2005
socal
Yes.

11. SeventhSonSIMMER DOWN 7+ Year Member

Aug 23, 2005
San Diego
MDApps:
it so happens for that expression a x b / c the order of operations is irrelevant

12. myershurt 7+ Year Member

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0
Sep 13, 2006
exactly as above - mathematically speaking - multiplication and division can be used together in any order - just plug in random numbers and you will see that the dose comes out exactly the same no matter which operation you do first...