# Math for nursing (allied health)

Posted
by asousa88 (New)

I am a pre-nursing major, about to apply to the nursing program. I have all my prerequisites but I am currently taking a math class for allied health. I am having the hardest trouble with this course. I don't understand any of it, and I can't comprehend any of these math equations. My question is, are all nursing courses involving these math skills? I am seriously double thinking nursing as a major because I don't think I can take another semester of this type of math :(

Which "math skills" are you finding difficult?

1 minute ago, chare said:

Which "math skills" are you finding difficult?

quite literally everything. the reconstituting and making solutions. I don't know if what makes everything harder is that the course is now online because of Covid - I'm basically having to teach myself. I am horrible at math to begin with, but this is really difficult for me.

If you post examples, and show what you have done to solve the problem, we might be able to help you understand.

ETA: Brad, one of the members here, is a retired pharmacist. He has written a textbook, Pharmacy Calculations for Pharmacy Technicians, which he has made available here. While written for pharmacy technicians you might find it helpful.

https://allnurses.com/master-your-drug-calculations-before-t671081/

4 minutes ago, chare said:

If you post examples, and show what you have done to solve the problem, we might be able to help you understand.

A doctor orders 25 ml of medication to be added to 100 ml. D5W and infused at a rate of 20 ml/hr. how long in hours and minutes will it take for this infusion to be complete?

I did: 125 ml/1 x 1hr/20 ml and I got 6.25...Teacher stated the answer is 6 hours and 15 minutes.

A child is to receive 500 ml of IV fluid. The set calibration is 60 gtt/ml and the flow rate is 75 gtt/min. If the IV was started at 3:30 pm, at what time will the infusion be complete? write in military time.

I did: 500 ml/a x 60 gtt/1ml x min/75 gtt = 30000/75

correct answer is 2210 (military time)

Does this get easier? Are nursing classes more anatomically-based? I understand anatomy but this math is really making me second guess!

17 minutes ago, asousa88 said:

I did: 125 ml/1 x 1hr/20 ml and I got 6.25...Teacher stated the answer is 6 hours and 15 minutes.

If you meant 6.25 hours, your teacher is being an a**.

21 minutes ago, asousa88 said:

A child is to receive 500 ml of IV fluid. The set calibration is 60 gtt/ml and the flow rate is 75 gtt/min. If the IV was started at 3:30 pm, at what time will the infusion be complete? write in military time.

I did: 500 ml/a x 60 gtt/1ml x min/75 gtt = 30000/75

You are missing a step here. This calculation gives the number of minutes that the infusion is going to run. What do you think you need to do to determine the end time of the infusion?

24 minutes ago, asousa88 said:

[...]

Does this get easier? Are nursing classes more anatomically-based? I understand anatomy but this math is really making me second guess!

Yes, it gets easier. This is new, and confusing, as you are many times being provided information that you don't need. As you progress, you will soon learn to extract the information that you need, and ignore that which you don't. This isn't done to confuse you as you will need to do this in practice.

4 minutes ago, chare said:

If you meant 6.25 hours, your teacher is being an a**.

You are missing a step here. This calculation gives the number of minutes that the infusion is going to run. What do you think you need to do to determine the end time of the infusion?

Divide the 30000/75 to get 400 mins..which is 6 hours and 40 mins?

1 minute ago, chare said:

Yes, it gets easier. This is new, and confusing, as you are many times being provided information that you don't need. As you progress, you will soon learn to extract the information that you need, and ignore that which you don't. This isn't done to confuse you as you will need to do this in practice.

Thank you so much. I feel like alot of the information and steps are just added so it confuses me - especially since math is my LEAST favorite subject LOL

Yes, 6 hours and 40 minutes is correct. You seem to be using dimensional analysis (DA), which I recommend, as there are no pharmacology math problems that can't be solved using DA.

If you have other questions or problems you need help with, please come back. There are many members here willing to help; all we ask is that you show us what you've done to solve the problem.

Best wishes,

On 8/3/2020 at 8:11 PM, chare said:

Yes, 6 hours and 40 minutes is correct. You seem to be using dimensional analysis (DA), which I recommend, as there are no pharmacology math problems that can't be solved using DA.

If you have other questions or problems you need help with, please come back. There are many members here willing to help; all we ask is that you show us what you've done to solve the problem.

Best wishes,

Thank you for your kind words. I am having a bit of trouble figuring this problem out. I've put 1000,000/10ml then don't know what to do next.

Order: Polymixin B sulfate 25,000 units/kg/d in 4 equally divided doses IM.

The label on the 1,000,000 unit vial states that reconstitution requires diluting with 10 ml of sterile water. How many milliliters will you prepare per dose for a client who weighs 140 pounds?

29 minutes ago, asousa88 said:

Thank you for your kind words. I am having a bit of trouble figuring this problem out. I've put 1000,000/10ml then don't know what to do next.

Order: Polymixin B sulfate 25,000 units/kg/d in 4 equally divided doses IM.

The label on the 1,000,000 unit vial states that reconstitution requires diluting with 10 ml of sterile water. How many milliliters will you prepare per dose for a client who weighs 140 pounds?

Well make sure you know how many units/mL that ends up being and just keep track for now.

First you have to convert his weight in pounds to kilograms.

Once you do that, the way I would personally do it, you want to get the total number of units for his weight, and then since the question is asking for a single dose, divide by the number of doses per day. That'll give you the amount of units you need per dose.

Then use whatever method you prefer to solve for how many mL you need for his dose. Everyone has their preferred way, but for me because I like ratios:

dose in bottle/10mL : dose needed/x mL

Then solve for x

A lot of people people like ordered/supply * volume

Edited by TheDudeWithTheBigDog

thank you you saved my life! LOL I have another question regarding dilution:

Order: Garamycin 25 mg IVPB q 85 for a child. If the label on the vial reads 5 mg/ml, how many ml will you withdraw from the vial to add to the volume control chamber? if the recommended concentration of the solution for infusion is 2 mg/ml, how would you then dilute the medication in the volume control chamber?

If there is a simple formula for this, please let me know and I can do all the work!

20 hours ago, asousa88 said:

thank﻿ you you saved﻿ my life! LOL I ﻿have another question regarding dilution:

[...]

Why don't you show us what you've done to solve this? As I said, there are many here who are willing to help, but you have to show what you have done.

Take a look at what you are being asked to determine.

20 hours ago, asousa88 said:

[...]

Order﻿: Garamycin 25 mg IVPB q 85 for a child. If the label on the vial reads 5 mg/ml, how many﻿ ml will you withdraw from the vial to add to the volume control chamber? if the recommended concentration of the solution for infusion﻿ is 2 mg/ml, how would you then dilute the m﻿edication in the volume control chamber?

[...]

What is the final answer you are being asked to determine? And what steps do you need to do to determine this?

Specializes in oncology. Has 44 years experience.

The math involved does seem tough at first but you will eventually get the hang of it. Does the class recommend you use DA? I think this is the recommended way now as it dovetails with your Chemistry. If so, when asking for help, ask people who can help you with DA. There are 2 other methods and I have seen students really get messed up by using half of one method and half of another. Sometimes the book presents all 3 ways. I see someone recommended ratio/proportion and I learned a formula method. Make a decision to follow one method and stick to it. I used to always say if I could create an easy way for students to learn dose calculations, I would retire a multimillionaire.

Learning this is hard for everyone. It is all new to you and you cannot see the equipment. Have you thought about stopping at a pharmacy and asking them to show you the label on a multi dose vial? Perhaps there are pictures of labels in your book? Best of luck, BTW I also got 6.25 hours for the first problem.