1st year nursing student...ratio proportion..help???

jenrninmi, MSN, RN · Sep 8, 2005

Here's a website you can try for some practice: http://www.delta.edu/tlc/TLCStudySupport/mathforscience/NursingMath/nursingmath.html

I would say also, if you're having problems with the nursing calculations there are some good study guides out there. I bet you could get a lot of help in the nursing student forum as well: https://allnurses.com/forums/forumdisplay.php?f=50

Taleah · Sep 9, 2005

THANK YOU FOR UR REPLY..I WILL LOOK THEM UP!!!!.................:)

Here's a website you can try for some practice: http://www.delta.edu/tlc/TLCStudySupport/mathforscience/NursingMath/nursingmath.html
I would say also, if you're having problems with the nursing calculations there are some good study guides out there. I bet you could get a lot of help in the nursing student forum as well: https://allnurses.com/forums/forumdisplay.php?f=50

purplemania, BSN, RN · Sep 9, 2005

do a google search on math +ratio and proportion. That should get you plenty of info.

Schools are favoring dimensional analysis now instead of R&P. Your instructor will show you how!

vampireslayer · Sep 10, 2005

I'm not sure exactly what "method" it is that I use, but the way I do my calculations seems really easy to me. I've taught it to a few people and they always say it's so easy, once they figure it out. I'll try to explain it if I can.

I ALWAYS start by looking at what the FINAL question is...often they give you so much information it's hard to know where to start. So I write down what they want, usually drops per minute, or mg per min or ml per min or whatever. Usually it's mls per hour, because that's how you'll program your pump or else drops per minute if they're assuming you're going to actually count drops.

So I write that down on the right side of the page, leaving plenty of room to fill in the left side of the equation, like this:

__________________________________= ml/hour

Then I look at ALL the information that the question gives me, and I start setting up fractions that give me the units I want, in the place that I want them. That means, that I know my FINAL answer has ml's on top of the fraction, and hours on the bottom. So, I look for any information that has one of those pieces of information. I always start with what the doctor has ordered, then I'll put in what solution I have available. Maybe I've got "the doctor orders 60 mg/hour", ok, that gives me "hours" on the bottom, right where I need it...so I write that down:

60 mg

_____

hour

Then I look for another piece of information that will allow me to get rid of those "mg"'s...because I know my final answer doesn't have mg's in it, just ml's & hours. So I want a fraction that I can place in my equation that when I multiply will allow me to cancel out the mg's. Your WHOLE solution is to multiply fractions that allow you to cancel out what you don't need, leaving only what you need.

So, my 2nd piece of info is always the solution that I have available. let's say I have a bag that gives me 100 mg of medication in a 250ml bag of saline. That gives me 100 mg/250 ml. Well, looking at fractions and multiplication rules, I know I need to have the mg's on the bottom, so that they will cancel out with the mg I already have (60mg/hour) when I multiply. So I flip that fraction to equal "250ml/100mg" and multiply that by my 60 mg/hour. That let's me cancel out the mg's in both fractions, leaving me with ml's/hour, which is what I needed in the first place.

Sometimes you'll have a doctor's order that's "mg's per minute" but your final answer has to be in ml's per hour. You'll just insert a fraction to convert the minutes to hours, canceling out the minutes, leaving the hours: 60minutes/1 hour.

I think this is probably confusing...it seems so simple to me! To recap, all I do is write down fractions and multiply them, looking for the pieces of info from the problem that give me the units I need, flipping the fractions upside down if I have to, so that I can cancel out the units I don't want, leaving the units that I do want.

Clear as mud?

VS

Taleah · Sep 11, 2005

THANK YOU...I APPRECIATE UR RESPONSE AND EXPLANATION...I WILL TRY IT TODAY. ITHINK I FIGURED OUT THE JIST OF IT BUT WHEN MY INSTRUCTOR STARTS TO THROW OUT GLUCOSE...CALORIE CONVERSIONS AND STUFF LIKE THAT...THIS IS MY FIRST SEMESTER SO I AM RACKING MY BRAIN...HA..HA...ONCE AGAIN THANK YOU!!

I'm not sure exactly what "method" it is that I use, but the way I do my calculations seems really easy to me. I've taught it to a few people and they always say it's so easy, once they figure it out. I'll try to explain it if I can.
I ALWAYS start by looking at what the FINAL question is...often they give you so much information it's hard to know where to start. So I write down what they want, usually drops per minute, or mg per min or ml per min or whatever. Usually it's mls per hour, because that's how you'll program your pump or else drops per minute if they're assuming you're going to actually count drops.
So I write that down on the right side of the page, leaving plenty of room to fill in the left side of the equation, like this:
__________________________________= ml/hour
Then I look at ALL the information that the question gives me, and I start setting up fractions that give me the units I want, in the place that I want them. That means, that I know my FINAL answer has ml's on top of the fraction, and hours on the bottom. So, I look for any information that has one of those pieces of information. I always start with what the doctor has ordered, then I'll put in what solution I have available. Maybe I've got "the doctor orders 60 mg/hour", ok, that gives me "hours" on the bottom, right where I need it...so I write that down:
60 mg
_____
hour
Then I look for another piece of information that will allow me to get rid of those "mg"'s...because I know my final answer doesn't have mg's in it, just ml's & hours. So I want a fraction that I can place in my equation that when I multiply will allow me to cancel out the mg's. Your WHOLE solution is to multiply fractions that allow you to cancel out what you don't need, leaving only what you need.
So, my 2nd piece of info is always the solution that I have available. let's say I have a bag that gives me 100 mg of medication in a 250ml bag of saline. That gives me 100 mg/250 ml. Well, looking at fractions and multiplication rules, I know I need to have the mg's on the bottom, so that they will cancel out with the mg I already have (60mg/hour) when I multiply. So I flip that fraction to equal "250ml/100mg" and multiply that by my 60 mg/hour. That let's me cancel out the mg's in both fractions, leaving me with ml's/hour, which is what I needed in the first place.
Sometimes you'll have a doctor's order that's "mg's per minute" but your final answer has to be in ml's per hour. You'll just insert a fraction to convert the minutes to hours, canceling out the minutes, leaving the hours: 60minutes/1 hour.
I think this is probably confusing...it seems so simple to me! To recap, all I do is write down fractions and multiply them, looking for the pieces of info from the problem that give me the units I need, flipping the fractions upside down if I have to, so that I can cancel out the units I don't want, leaving the units that I do want.
Clear as mud?
VS

LPN0207 · Sep 11, 2005

yep...that sounds like dimensional analysis...we had to learn it for chem, but for nurse calc we haven't used that yet. Go figure huh? Another name for it is demented analysis, lol :)

Daytonite, BSN, RN · Sep 12, 2005

Ratios are nothing more than fractions. You can put any number with any label on it into the denominator or the numerator. The denominator and numerator do not have to have numbers with the same labels attached to them. To work them as proportions you are setting one ratio (fraction) equal to another ratio (fraction). The simple rule is that you must have numbers with the same labels in both corresponding denominator and numerator. You can cross multiply two fractions that are set equal to each other. The product of each cross multiplcation will be equal if your ratios are in proportion. So, 1/2 = 5/10 is a ratio. The cross multiplication products are 10 which proves these two fractions are proportional.