# The Nursing Math Thread - page 11

A member pm'd me the following question highlighted below. We created this thread for you guys to talk about math, solve math problems, and post math websites that you have found helpful. I was... Read More

1. I also use Calc. with confidence and it is a great book. I have a lot of problems with math and making it make sense to me. It is really good practice for figuring out dosages.
2. I also use this book and it's great.
3. thanks for this website. i have not yet started phamacology but it doesnt hurt to collect whatever important information you land on
4. i love www.dosagehelp.com it has helped me out alot, and i still use it to brush up on math! it has questions and how to sovle them all explained in detail for you.
5. Thanks very much for the help. Now just wish me some luck!!!!!
6. Two cyclists start biking from a trail's start 3 hours apart. The second cyclist travels at 10 miles per hour and starts 3 hours after the first cyclist who is traveling at 6 miles per hour. How much time will pass before the second cyclist catches up with the first from the time the second cyclist started biking?

How do you solve this?? and

What simple interest rate will Susan need to secure to make \$2,500 in interest on a \$10,000 principal over 5 years?

(it's a practice test for nursing school)
7. Quote from Ms. Nurse Assistant
Two cyclists start biking from a trail's start 3 hours apart. The second cyclist travels at 10 miles per hour and starts 3 hours after the first cyclist who is traveling at 6 miles per hour. How much time will pass before the second cyclist catches up with the first from the time the second cyclist started biking?

How do you solve this?? and

What simple interest rate will Susan need to secure to make \$2,500 in interest on a \$10,000 principal over 5 years?

(it's a practice test for nursing school)
There are weblinks for help with basic algebra on post #3 of this thread. Post this question on the pre-nursing forum. This thread is for help with drug calculation problems.
8. Not sure if anyone is still reading this...but I have a math question about drop factors.

Order: 1000 ml to infuse at 150 ml/hr. Drop factor is 20. How many gtts/min?

I have the answer and I worked it out to the best of my ability and I was very close, but we all know that very close doesn't count. Any help you all could give me would be wonderful. Thanks in advance. :wink2:
9. Quote from evilglowduckie
Order: 1000 ml to infuse at 150 ml/hr. Drop factor is 20. How many gtts/min?
150 mL/hour (infusion rate) x 20 gtts/mL (drop factor of IV tubing) x 1 hour/60 minutes (conversion factor) = 50 gtts/minute (drip rate)
10. 150 mL/hour (infusion rate) x 20 gtts/mL (drop factor of IV tubing) x 1 hour/60 minutes (conversion factor) = 50 gtts/minute (drip rate)
Thank you so much! I always get confused when it when I am given the ml/hr and have to use that instead of the total volume. I need to find a way to get this to stick in my brain.
11. Quote from evilglowduckie
Thank you so much! I always get confused when it when I am given the ml/hr and have to use that instead of the total volume. I need to find a way to get this to stick in my brain.
I think that if you were staring at this equipment in a lab it might be easier. Looking at these problems on paper they really don't make a lot of sense.
12. Help!!
Order: Tetracycline Elixir qid for a child weighing 50 lb at a dosage of 8 mg/kg/day in equally divided doses.
How many mg would one does contain? Tetracycline is supplied at 50 mg per 7 mL. How many mL should be administered?

I did 5ml/50mg * 181.6mg/dose = 18.16ml/dose

The answer is Patient weight 22.7 kg
Daily dose 181.6 mg
Each dose 45.4 mg
Give 6.4 mL

From this site: http://www.msumedcalc.com/quiz6.html
13. Order: Tylenol suspension 1/2 tsp po q4h prn for fever for a child weighing 32 lb.
The medication is supplied as 325 mg per 10 mL
The recommended dose is 25 - 35 mg/kg/day q4h prn
Is the ordered dose in the safe range?