Help Dimensional Analysis

Daytonite, BSN, RN · Jan 17, 2009

i work medication calculation problems for students on the forums by dimensional analysis all the time. i think the best explanation for da (dimensional analysis) is also in referring to it by its other name, factor labeling. when you are using da to solve medication calculation problems, and from what i recall of using it years ago in chemistry, the factor labeling component to it is significant. in setting up equations by da you are deliberately manipulating the terms of the equation in order to factor out the unwanted labels accompanying them as well as add labels you need that aren't there. you are kind of playing a game of musical chairs. by the end, you only want specific labels left, so you may be putting conversion factors into an equation in order to cancel out specific labels you want to get rid of. certain terms in the equation are like married couples and must remain together as numerator and denominators as the equation is set up. but, after all the arithmetic and factor labeling, a new relationship emerges by the end. when i set up a problem by da i begin by writing out what labels i want on my final answer and what positions they need to be in. then, i begin setting up the terms of the problem paying attention to the labels on the terms so that i am going to end up with a final answer that has the labels i want in their correct positions. there are times when i have to go back and flip all the numerators and denominators in the equation in order to get the correct final result.

there are weblinks to tutorials on da and medication calculations on post #2 of this sticky thread on this forum:

https://allnurses.com/general-nursing-student/nursing-math-thread-264395.html - the nursing math thread