# Math Question

by MikeyJ, RN (Member)

MikeyJ is a RN and specializes in Peds, PICU, Home health, Dialysis.

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I have my orientation today and we are required to take a math test today (no calculators permitted). I can do everything with ease; however, I am confusing myself with a few ratio questions. Here are a few examples -- could someone tell me if I am doing them right?

Solve for X in each of the following. Be sure to label answers:

200mg:2ml::150mg:Xml

x=1.5 ml ?

50mg:1ml::35mg:Xml

x=0.7 ml ?

30mg:2ml::20mg:Xml

x=1.33 ml ?

Do those look right? I spoke with a 3rd semester nursing student and she told me they were not and showed me how to do them; however, her answeres were not making any sense. I am trying to think back to basic algebra, and I think I am setting them up right.

Any insight? Thanks!

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iHeartNICU specializes in NICU.

293 Posts; 4,685 Profile Views

Totally right. Congratulations!!

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CseMgr1 has 39 years experience as a ASN, RN and specializes in Case Management, Home Health, UM.

1,287 Posts; 11,278 Profile Views

I have my orientation today and we are required to take a math test today (no calculators permitted). I can do everything with ease; however, I am confusing myself with a few ratio questions. Here are a few examples -- could someone tell me if I am doing them right?

Solve for X in each of the following. Be sure to label answers:

200mg:2ml::150mg:Xml

x=1.5 ml ?

50mg:1ml::35mg:Xml

x=0.7 ml ?

30mg:2ml::20mg:Xml

x=1.33 ml ?

Do those look right? I spoke with a 3rd semester nursing student and she told me they were not and showed me how to do them; however, her answeres were not making any sense. I am trying to think back to basic algebra, and I think I am setting them up right.

Any insight? Thanks!

You're right:

200 ml : 2 ml :: 150 ml : x ml.

200x = 300

x = 300/200 = 1.5

x= 1.5 ml.

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Daytonite has 40 years experience as a BSN, RN and specializes in med/surg, telemetry, IV therapy, mgmt.

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Your answers are correct, but you really didn't show how you did the calculations to find the "X"s, so I don't know if your process of doing the math was correct. Doing them as ratios you would have cross multiplied. You can also set them up by dimensional analysis, factor out labels and common factors, and then multiply together everything that is left.

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DisneyNurse18 has 10 years experience.

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I dont like the dots, maybe that is what was confusing you?? I like using the dimensional analysis method. The dots drive me crazy!!!! When the teacher would go about doing dots I put my fingers in my ears and go dododododododod lol To me the other way is soooo much easier! For some reason it just makes more sense that way. Good luck though.

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MikeyJ is a RN and specializes in Peds, PICU, Home health, Dialysis.

1,124 Posts; 9,343 Profile Views

Thanks for everyones replies! I received a 100% on the math test today. :)

Sorry I didn't show how I did my work -- I just set them up as simple ratios and cross-multiplied. I found that to be easiest.

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383 Posts; 5,692 Profile Views

You're right:

200 ml : 2 ml :: 150 ml : x ml.

200x = 300

x = 300/200 = 1.5

x= 1.5 ml.

Math is not my strongest subject. I am a pre-nursing student waiting to hear from 2 schools. Can someone please help me understand this equation? How does 2ml become 200x? Does it have to do with the ml? Is this something I learn in dosages?

Thanks

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Megsd is a BSN, RN and specializes in Neuro.

723 Posts; 5,909 Profile Views

Math is not my strongest subject. I am a pre-nursing student waiting to hear from 2 schools. Can someone please help me understand this equation? How does 2ml become 200x? Does it have to do with the ml? Is this something I learn in dosages?

Thanks

The way the equation is set up with the : is much like a fraction. 200 is on the top, 2 is on the bottom. 150 is on the top, x is on the bottom. To find the answer, you multiply the top numbers by the bottom numbers of the opposite fraction. So: 200 (top left) * x (bottom right) = 150 (top right) * 2 (bottom left)

This winds up being 200x = 300. Then divide both sides by 200 to get x = (300/200) which equals 1.5

Hope that makes more sense.

While you'll learn the specifics of dosages in school, most of this is algebra. You may want to refresh yourself on things like fractions and proportions before doing dosage calculations in school. Get a dosage calc book with refresher sections -- I had forgotten how to do fractions too until I got into school.

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304 Posts; 4,407 Profile Views

Thanks for everyones replies! I received a 100% on the math test today. :)

Sorry I didn't show how I did my work -- I just set them up as simple ratios and cross-multiplied. I found that to be easiest.

Good job!!!!