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As a woman, I know there is nothing more life-changing than giving birth to a child. It’s a time when you most need the support of people around you. You need encouragement. I had the pleasure of interviewing Audrey Kalman for this week’s Math at Work Monday. She’s been a birth doula for twelve years so she’s been the support for countless women (and watched a lot of lives enter the world!). What does this have to do with math?  Let’s find out!

Can you explain what you do for a living?

I support women who are giving birth and their families as a birth doula. Birth doulas are non-medical support people, hired by families, who provide informational, emotional, and physical support before and during birth. I meet with families before their babies are born to find out what they’re hoping for; I help ease anxieties and point them to resources. Once a woman goes into labor—or thinks she’s in labor—she contacts me. I then join her at her home or at the hospital and stay with her and her partner until a couple hours after the baby comes. That could be a few hours… or a few days. I do everything from reassuring her (and the dad!) that everything is fine to massaging her back to talking her through a particularly painful or challenging moment. I often describe my role as a “professional sister.” I have up-to-date training and come without the “baggage” of a family member, but I bring the same kind of caring and compassion you might expect from a close relative.

When do you use basic math in your job?

Because I’m self-employed, math is part of the equation (pardon the pun) that helps me figure out how to set my rates and how many clients I need to work with to meet my income goals. For example, when recently deciding whether to raise rates, I researched living wages in my area. I then calculated how many births I would need to attend to make a living wage, looked at fees charged by doulas just starting out, and used a multiplier developed by another doula to account for my years of experience. Then there’s all the lovely arithmetic that goes into tax calculations, though I use a tax calculation program for that.

Do you use any technology (like calculators or computers) to help with this math? Why or why not?

I don’t know where I’d be without Excel spreadsheets. Since I also serve as the administrator for a small group of doulas (we back each other up), I’m responsible for maintaining a spreadsheet to track all of our clients and tallying up who owes what to whom at the end of each quarter. We serve about fifty couples each year so this can get complicated. Using a spreadsheet is the only way to keep track of everything—not only who owes what but also other information like due dates.

How do you think math helps you do your job better?

I absolutely think it helps me do my job better. The hands-on work of being a doula is very intuitive, but the rest is like running any other business. I believe it’s important to be professional which includes creating contracts and invoices for which basic math is certainly required.

How comfortable with math do you feel? Does this math feel different to you?

I’ve always felt comfortable with math. (My mother was a college professor who taught physics and mathematics.) The math I use now feels somewhat pedestrian—it’s really just glorified arithmetic. What’s interesting to me is using problem-solving concepts to help me figure out big-picture questions (as with the rate-setting example I gave above).

What kind of math did you take in high school? Did you like it/feel like you were good at it?

I have always really enjoyed math. I had an unusual education in that I attended an early college now known as Bard College at Simon’s Rock so I took only algebra in high school. I went on to do some interesting math in college, including systems dynamics, but I didn’t pursue higher level math since I was a creative writing major. I did take statistics for my graduate degree in journalism. I think all citizens should be required to take basic statistics!

Did you have to learn new skills in order to do the math you use in your job?

I definitely picked up my spreadsheet skills post-school since nobody was using personal computers when I went to college, but the big-picture thinking and problem-solving skills which I consider to be part of math were definitely something I honed in school and have used ever since.

Anything else you want to mention?

I want to mention another kind of “math” that is related to birth. I think of it as “intuitive math.” It’s what allows me to “feel” whether a woman’s contractions are getting closer together and longer (a sign that labor is progressing). It also allows me to help women through contractions by counting their breaths. Perhaps this doesn’t have much to do with what we typically think of as math, but part of math is all about patterns and cycles—and those are definitely relevant to the process of giving birth.

Intuitive math.  Pretty cool!  I’ve never even thought about that. I hope you enjoyed this interview as much as I did. If you have any questions for Audrey, please let me know.

Photo Credit: phalinn via Compfight cc

When it comes to life and death situations, we want to have confidence in those that are taking care of us. How do they know when to give us medicine, or exactly how much we need? Rebecca Paisley has been a registered nurse for five years and describes her use of practical math in the workplace. 

Can you explain what you do for a living?

I work on an inpatient trauma unit. We take care of the patients once they are seen in the ER. The patients either go to the Intensive Care Unit, the Operating Room or come to our floor. We have a variety of patients – from car wrecks, falls, gun shot wounds, stab wounds, motorcycle wrecks, traumatic brain injuries and some very intense medical surgical patients with complex diagnosis. We care for these patients throughout their stay which can be from 1 day to months. We are constantly on the go, getting patients out of bed, doing procedures at the bedside (extensive dressing changes, chest tube insertions, general patient care), occassionally transfering patients to ICU, if they need a higher level of care. We also admit and discharge patients throughout the day. Needless to say, we are busy!

When do you use basic math in your job?

I use math every single day at work. It’s basic math (simple multiplication, division, addition, subtraction), but I have to use it to take care of my patients. Mainly it’s medication related. For example, you’ve got Tylenol 1000 mg ordered, but the patient needs to use a liquid form (650 mg in 20.3 mL) of the medication, you then have to figure out how many milliliters you need to give the correct dose. Once you do the math a couple of times, you remember the mLs that you need. It’s easy to do it that way with a rountine medication, but sometimes we are doing the math extremely fast in an emergent situation (like a chest tube insertion or code situation). We always double check the medication during these times with a second nurse. Another example is when we give pain medication. Say the patient has diluadid ordered our standard protocol is 0.3 mg to 0.9 mg per dose. Using our judgement, we decide on the dose amount. The medication is stock in 2 mg per 1 mL vial. By using basic division I know that the concentration is 0.2 mg per 0.1 mL. I also use it to figure out the drip rate for IV fluids and antibiotics. Ancef is ordered, it comes in a 50 mL bag, it needs to infuse in 20 minutes. Here is the math in my head: 60 minutes (1 hr) divided by 20 is 3. Multiply 3 by 50 (the mLs needed to infuse) and you get 150 ml/hr. Or if we need to bolus some IV fluids, but the doctor wants them over a certain amount of time. Say 500mL over 4 hours, (500 divided by 4 equals 125, so 125 ml/hr). I also use math to estimate my time spent with my patients in the morning (15-20 mins a patient, totaling 1 hour to 1 hour and 20 minutes ), so I can grab my morning cup of coffee! 🙂  However, this math is not always correct!

Do you use any technology (like calculators or computers) to help with this math? Why or why not?

We have certain medications that are continuous drips, like heparin or insulin. The pharmacy has calculators for these high risk medications for us to use. We just have to plug in the correct numbers, and we get the new dosing rate. The formulas for these calculations are available on our protocols, so if the calculators are unavailble (which rarely happens), we have the formula to use to get the new dosing rate. These calculators are used to reduce human error on these high risk medications. They are extremely important for safe patient care, ONLY as long as the nurse is plugging in the correct values! That’s why there is always a second nurse verification! Some of the medications (like the Tylenol example) will have the milliliters needed for the dose in the order information, but I like to challenge myself, and calculate the dose myself.

How do you think math helps you do your job better?

It makes my patient care more efficient. When I am able to do basic math in my head, I can administer medications faster, especially in an emergent situation where time is everything.

How comfortable with math do you feel? Does this math feel different to you ?

I feel pretty comfortable with math, but just basic math. The math I use at work has become “second nature,” so I’m able to use it and not really think about it. More complex calculations require good ‘ole paper and pencil!

What kind of math did you take in high school? Did you like it/feel like you were good at it?

I took geometry, and trigonometry, and I’m guessing Alegbra. I honestly hated math in school, but was fairly good at it. I never wanted to aspire to take calculus or advanced Algebra.

Did you have to learn new skills in order to do the math you use in your job? Or was it something that you could pickup using the skills you learned in school?

In nursing school, we had a pharmacology class, the whole first portion of it was math. We had to pass a math exam to even continue in the class. Everyone was so stressed out about it. We had to hand calculate drip rates, dosages, and do conversions. This math wasn’t foreign to me, as far as proportions and basic alegbra, but it was definitely stressful! Once we learned the “easy” ways to figure these calculations out, it was all good. I had to learn these new ways of solving these problems, it obviously did not come naturally!

Do you have a question for Becca? Send me your question and I will forward it to her.

Math is important in many careers, but one of the most critical is in the field of medicine.  For example, it’s very important for medicine to be dosed in correct amounts.  I’m thankful that Michelle knows her math since she is assisting physicians on a daily basis.  Even though I hope I don’t have to visit her… it’s good to know she’s there.

Can you explain what you do for a living?

I am a physician assistant. It is an advanced degree where I am able to interview, examine, order tests, perform minor procedures, assist in surgery, develop treatment plans and write prescriptions. Basically, I function much like a doctor.

When do you use basic math in your job?

All the time. I have to quickly convert pounds to kilograms because a lot of medicines are dosed in kilograms. This is especially important in trauma situations. Many medicines are weight-based like 50mg/kg divided in 3 doses per 24 hours. It gets complicated. I’m thankful that I don’t work in pediatrics because there are further calculations involving liquid and then interpreting the directions into teaspoons/mL/cc so that it makes sense to the parent based on the measuring device that is accessible to them.

Do you use any technology to help with this math?

Yes, I use calculators. I also use paper and pencil the old-fashioned way to visualize the conversions. Electronic medical record has settings that help and alert you if what you are ordering doesn’t make sense.

How do you think math helps you do your job better?

I don’t know about better, but it’s necessary.

How comfortable with math do you feel?

I rarely feel comfortable, but I feel safe that there are resources available to check my work so that I don’t make mistakes.

What kind of math did you take in high school?

I took Algebra, Geometry, and Algebra II.

Did you have to learn new skills in order to do the math you use in your job?  

No, not really. Occasionally I have to brush up on statistics in order to interpret research or scholarly articles and data. There isn’t much of a role for advanced math, such as trigonometry, in my daily job.

Questions for Michelle?  Let me know, and I’ll ask her!

In today’s world, we’ve all unfortunately been touched by cancer in one way or another.  We may have stood beside a loved one as they battled the disease, or we may have experienced it first-hand.  Rick at First Dayton Cyberknife encounters cancer patients on a daily basis as he assists in their treatment.  I’m thankful for folks like him who use their math skills effectively to help others.

Can you explain what you do for a living?

I am a certified medical dosimetrist at First Dayton Cyberknife. I work in radiation therapy which is used to treat people who have cancer. I make sure the radiation kills the cancer cells without harming the patient.

The medical dosimetrist is responsible for designing a treatment plan and carrying out calculations with mathematical accuracy for the delivery of radiation treatment based on the oncologist’s prescribed course of therapy. This treatment plan takes into consideration tumor pathology, tumor volume, and inherent dose-limiting structures surrounding the tumor. The treatment plan and radiation field-placement techniques are constructed utilizing sophisticated computer equipment and technology. The medical dosimetrist, along with the radiation oncologist and medical physicist, will work to construct a treatment plan that will meet the prescription written by the oncologist, ensuring that the patient will not lose important healthy organ function and that the radiation delivered will not affect healthy surrounding tissue. These treatment plans not only include the use of radiation but also, in many cases, involve the use of radioactive elements during interstitial brachytherapy procedures. Once the treatment plan is complete, the medical dosimetrist will work closely with the radiation therapists in the implementation of the prescribed plan.

When do you use basic math in your job?

My whole job is math related. I wouldn’t be able to do my job without math skills. Most of my job pertains to the physical properties of radiation and its interactions with matter. There are calculations depending on energy, energy type (photon, electron, gamma ray), size of the treatment field etc. Most of these calculations are done using a treatment planning system (TPS). We use Eclipse, which is from a company called Varian. We also use a Cyberknife, which uses a software called MultiPlan.

Do you use any technology to help with this math?

Most of the time I use specialized software for treatment planning but not always. Some plans have to be hand calculated.  

Sometimes I use a hand calculation to basically determine how long the machine needs to stay on to deliver a certain dose to a certain depth. For example, the radiation oncologist will prescribe 2400 cGy (centigray is a unit of absorbed dose) in 10 treatments (240 cGy per treatment) to a depth of 80% or sometimes he will say 2 centimeterss. I will use a simple formula that we call a hand calc, 240 

80% • 1.002 =299cGy
(where 1.002 is the output factor of field and energy)

1 cGy=1 monitor unit on the machine so the machine would be set to 299 mu’s per treatment for ten treatments for 100% coverage of radiation at the 80% isodose line. This is confusing as heck so I won’t get any deeper with this because I will just go on and on and on….

This is a very simple calculation. Most of the time we aren’t this lucky. Actually most of the time everything is calculated with the Treatment Planning System.

How do you think math helps you do your job better?

Math is physics and physics is math, so you can’t have one without the other.

How comfortable with math do you feel?

I feel very comfortable with some math, but with other math I still feel very uncomfortable.

What kind of math did you take in high school?

The highest I took was Algebra II. I barely passed!

Did you have to learn new skills in order to do the math you use in your job?

I have had to learn new calculations for new procedures depending on the type of treatment. Some treatments use a real source of radiation which has different factors. In college, medical physics and radiation physics were totally new to me. I can’t really compare it to normal math class. Lots of formulas, laws and other “math stuff.”

One law that is common is radiation is called the inverse square law: In physics, an inverse-square law is any physical law stating that a specified physical quantity or intensity is inversely proportional to the square of the distance from the source of that physical quantity. That is one of the first things you learn.

Want to know more about using math in the fight against cancer?  Let me know, and I’ll be sure to ask Rick your questions.

Yes, you read that right — pediatric plastic surgeon. But don’t make the dumb assumption that I did when I first met Dr. Rick Redett. He’s not doing nose jobs on preteens. He’s expertly repairing cleft lips and palates, doing skin grafts and addressing nerve injuries at Johns Hopkins Children’s Center. And this is pediatrics, so he’s working with teeny-tiny parts — little hands and noses and even nerves in these little bodies. One measurement that’s even a little bit off can mean a very big problem. 

It’s no wonder that Dr. Redett uses lots of math in his work — from conversions to measurements to basic geometry. On top of that, he helped found Bring Hope Through Healing, a non-profit that helps fund surgical trips to South and Central America, so that children (and even a few adults) with cleft palates and lips can get restorative surgery. But in terms of his everyday job? Here’s how he uses math. 

Can you explain what you do for a living? I am a pediatric plastic surgeon, caring for children with cleft lip and palate, nerve injuries, congenital and traumatic hand problems and burns.

When do you use basic math in your job?  Most of the medicines we give children are weight based, which means we give a specific amount of medicine calculated using the weight of the baby. Giving too little or too much medicine may be harmful. I also use math during surgery. When a baby is born with a cleft lip, one of the nostrils is much bigger than the other. To determine how much smaller I need to make the bigger nostril, I use device which measure the diameter of each nostril. Multiplying the difference in diameter of the nostrils by 3 (approximately π) will equal the amount of tissue which needs to be removed from the bigger nostril to make it the size of the smaller nostril.

Notice how the nostril on the left is larger than the one of the right. Rick uses the formula for the circumference of a circle to help him even out the nostrils along with repairing the cleft lip.

Do you use any technology to help with this math? I use an app on my iPhone when calculating medication doses in children

How do you think math helps you do your job better?  I couldn’t do my job without math.

How comfortable with math do you feel?  I enjoyed math in school and am comfortable using it at work. Most of the math I use at work is relatively simple but necessary to practice medicine safely.

What kind of math did you take in high school? Math was one of my favorite classes in high school. I especially liked trigonometry

Did you have to learn new skills in order to do the math you use in your job? I didn’t have to learn anything new, but I have had to review things that I didn’t know I’d need. When I was learning how to make the nostrils symmetric during cleft lip surgery, I had to look up the formula for the circumference of a circle (C = dπ, where C is circumference, d is diameter and π can be rounded 3.14).

Did you think that the formula for the circumference would ever be useful? I was surprised. Oh, and parents, next time your little one is at the doctor or (god forbid) needs surgery, be glad that the doctor took math! If you have questions for Dr. Redett, post them here. I’ll let him know about them and get answers for you. 

With a blind, deaf, 18-year old toy poodle who has dementia (canine cognitive disorder), I’ve gotten to know our friendly neighborhood veterinarian very, very well. Dr. Robert Z. Berry, DVM at The Village Vet has helped us manage some strange symptoms and supported us in the last year since Roxie was diagnosed with dementia. Just like people doctors, vets must have excellent bedside manner, and Dr. Berry has it in spades.

I also noticed that he does quite a bit of math in his work. Roxie has been on a variety of medication, as we’ve looked for the right combination to keep her happy and healthy. And she’s only 6 pounds. That means converting measurements like crazy. At a recent visit, I finally got the idea to ask Dr. Berry to answer my Math at Work Monday questions. If your kid aspires to be a vet, read on!

Can you explain what you do for a living? 

I examine sick and healthy animals, provide preventative care such as vaccinations or parasite (intestinal and blood born worms) screening and offer early disease detection, blood tests or imaging (xrays and ultrasound). In the case of sick animals, we can hospitalize and provide medical care or medical surgical care to help return them to normal health. Additionally we provide routine surgical and dental services such as spaying , neutering, tumor removal, dental cleaning and extractions.

When do you use basic math in your job?

Everyday, from basic math skills to algebra. Here’s an example : An animal weighs 22 pounds and needs medication which is dosed at a rate of 20 mg/kg and given three times a day. The animal’s weight is measured in pounds, so the first step is to convert to kilograms. Then I need to multiply the weight in kilograms by 20 mg/kg. Now we have a milligram dose of 200 mg. But things can get even more complex. Suppose the drug is supplied in 400 mg/ml strength? I use division or an algebraic formula to arrive at a milliliter (or cc, cubic centimeter) dose of 0.5 ml.

Do you use any technology (like calculators or computers) to help with this math?  

I really prefer not to use a calculator because I think it can make my brain become lazy. It is remarkable how much agility you lose (even basic math skills) when you don’t use basic math skills on a daily basis. I calculate in my head but verify with the calculator.

How do you think math helps you do your job better?

It’s absolutely necessary with any sort of drug therapy.

How comfortable with math do you feel?

I feel very comfortable with math and have all of my life. Vets must be mentally sharp and learn to rely on their most important assets — their brains! I took calculus in high school, and I felt very confident in the class. School prepared me very adequately for the nuts-and-bolts part of my job. I was fortunate to have good teachers and also to have been raised in the time period before calculators were allowed in school. A good primary education prepares one for the rest of his or her life.

So there you have it, a vet who is both compassionate and math-savvy — a great combination! Were you surprised by the math that Dr. Berry uses in his practice? Share your response in the comments section.

When I was really young, I wanted to be a nurse. Those who know me now are probably laughing. It’s not that I’m squeamish about blood, but I absolutely cannot handle any other, um, bodily fluids. Ick. Thank goodness for people like Beth Hanes, who have made a career of caring for others who are sick or undergoing surgery. [Editors note: Since this interview appeared a year ago, Beth has decided to freelance write full time.Now that I can identify with!]

Beth Hanes is a registered nurse in a plastic surgery center.  She takes care of patients before, during and after their surgeries.  And, of course, she uses math everyday.

What kind of math do you use in your job?

I use basic math for a lot of things, but probably the most important calculations are the ones related to medication use. Sometimes I dilute medication before giving it. For example, Promethazine needs to be diluted before it’s given in an IV. Using a 10mL syringe, I draw up 1mL of Promethazine and then add 9mL of normal saline (0.9% sodium chloride) to create a 10% Promethazine solution.

I also use basic math to determine, based on body weight, how much medication to administer. Medications are generally given on a milligram per kilogram basis. So, I convert a person’s weight in pounds to weight in kilograms (divide pounds by 2.2 to obtain kilograms), then I multiply this number of kilograms by the number of milligrams per kilogram to get the correct dosage. For example, Lidocaine might be ordered as 1mg/kg. A 220-pound patient weighs 100kg, so the correct dosage is be 100mg of Lidocaine.

How do you do your calculations?

I do use calculators because they’re typically faster, but I think it’s important to know how to do math by hand. I usually don’t have a calculator on hand in the operating room! Also, it’s critically important for me to have basic formulas memorized (such as how to convert pounds to kilograms). Without that knowledge, having a calculator or not is irrelevant.

Why is math important for your job?

Math skills help me ensure patient safety. There was a highly publicized case a few years ago in which actorDennis Quaid’s infant twins were administered a very high dose of Heparin. This error occurred for many reasons, but one key factor was doing the math involved. This is a classic case of calculating dosage based on weight, and obviously errors were made in that calculation. In nursing, if you misplace a decimal point, you can kill someone.

When it comes to math in nursing, I think the main thing is to be very careful about calculations, double-check them, and then have someone else double-check them. No matter how good you may be at math, anyone can misplace a decimal point when calculating on-the-fly. It’s much better to take the extra seconds to have someone review your calculations and keep patients safe than to have any sense of ego about your math ability and endanger a patient.

What kind of math did you take in high school?

I had a rather sketchy math education, because my parents moved around a lot, and I only made it through Algebra II. On the other hand, advanced math was not yet common at the high school level when I was that age. Calculus, for example, was a college course. I did not feel I was good at math in high school. However, this “low math esteem” led me to focus on practicing real-world math skills.

These days, I am fairly comfortable with math, in general, though I frequently have to think through conversion problems, which are common in nursing. I find I often want to divide when I should multiply, for instance, so I have to be careful about that! Once I have a formula memorized, however, I feel very comfortable substituting variables with real values and arriving at the correct answer.

If you have questions for Beth, ask them in the comments section. Read other Math at Work Monday entries in the archive.  And if you or someone you know wants to be interviewed for this regular, Monday feature, let me know.

Dr. Josh Sharfstein

Ooooh!  We have a big-wig here at Math for Grownups today!  Dr. Joshua Sharfstein is a pediatrician and the Secretary of the Maryland Department of Health and Mental Hygiene.  Before taking this position, he served as the Principal Deputy Commissioner of the Food and Drug Administration (FDA). And before that, he was the Commissioner of Health in Baltimore.

I met Dr. Sharfstein when he was Health Commissioner of Baltimore.  He and I talked about having an epidemiologist on staff to help track (and therefore prevent the spread) of infections and diseases in the city.  I remember being fascinated by the statistics involved in his job.  Read on for more details.

Can you explain what you do for a living?

I run the health department in Maryland.  Our goal is to improve the health of Marylanders through health insurance for low-income individuals and families, services, community support, and education.

When do you use basic math in your job?

I often use math to understand the health of Maryland.  We are now tracking 39 specific measures of health, such as the rate of smoking and the number of children who are poisoned by lead paint. You can see these measures at the Maryland Department of Health website.  In addition to using math to understand each of these numbers, I often use statistics to see if Maryland is moving in the right direction, the wrong direction, or just staying the same.  I also use statistics to identify specific groups of people who are facing the greatest health challenges in our state.

Math is also involved in setting budgets.  Our Department’s budget is about $9 billion each year. That’s a lot of money to be responsible for.  I need math to identify the areas where costs are growing beyond what we anticipated.

How do you think math helps you do your job better?

Math is essential to my job. If I did not feel comfortable with math, I could not be responsible for the funding of our Department or the health of the people in Maryland.

How comfortable with math do you feel?

I have always loved math. It was my favorite subject in school.  I like surprising people at work by showing them my own calculations.  My children are now taking math, and I really enjoy learning along with them and teaching them math tricks from my days as a student.

What kind of math did you take in high school?

I took calculus and advanced calculus in high school.  I took a special math class at the University of Maryland in College Park when I was in high school.

Did you have to learn new skills in order to do this math?

In college and afterwards, I took classes in statistics.  I use math from high school and statistics from college and beyond to do my job.

Do you have questions about Dr. Sharfstein’s job?  If so, post them in the comments section.

And while you’re at it, if you have special requests for Math at Work Monday features, drop me a line at llaing-at-comcast-dot-net.  Also feel free to send the names and contact info for those who might be willing to be interviewed!

Julie Norin

For many of us, math is like hearing — something we take for granted on a daily basis.  As an audiologist, Julie Norin pays close attention to both on a day-to-day basis.  Here’s how she uses math in her work and what she thinks of it. 

What do you do for your living?

I work as a clinical audiologist which means I help people who have hearing loss and other related ear problems. Essentially, I measure a patient’s ability to hear and distinguish between sounds. After analyzing the test results along with other medical data, I make a diagnosis and determine a course of treatment. Most often, the course of treatment involves fitting a patient with hearing aids, which I then program according to their hearing needs, but I may also refer my patients for continued medical care by their primary care physician, an ear, nose, and throat physician, a cochlear implant specialist, or a neurologist. I also spend a great deal of time counseling my patients and the family members of my patients regarding the diagnosis of hearing loss and treatment plan.

When do you use basic math in your job?

I use basic math daily. When testing a patient, I use simple addition and subtraction to determine differences between the ears, as well as to determine the presentation levels of the various test signals. When testing a patient’s speech discrimination abilities, I use division and calculate percentages, and with other tests I rely on a formula of ratios and statistics to determine whether results are normal or not. I also make buying decisions for the clinic where I work.  I use math to calculate clinic expense and net revenue. Our clinic provides a sliding-scale reduced fee, which is based on a person’s financial standing. This can vary between a 20% and 80% discount, so I am always applying basic math to calculate those patients’ fees.

Do you use any technology to help with this math?

My diagnostic equipment is computerized and has some technology built in, so the math can be calculated during speech discrimination testing, as long as I am tracking patient responses using the computer. But every so often, I wind up doing the caluclations myself. Hearing aids are typically programmed using a designated fitting formula, which is calculated based on age, size of the ear canal and degree of hearing loss. In terms of factoring clinic expenses and net revenue, I will pretty much always rely on a calculator if there is one close by. I like to be absolutely sure about the numbers. Especially since I work for a non-profit agency.

How do you think math helps you do your job better?

I wouldn’t be able to do my job if I didn’t have an understanding of math, especially when I’m testing, because the equipment is not able to determine differences between the ears or calculate presentation levels. It also helps me to understand test results, and determine what instruments are suitable to accomodate a patient’s needs.

How comfortable with math do you feel?

I have never really felt comfortable with math. I still don’t. Hearing science and the study of acoustics are both incredibly math based, so during my studies I had to learn how to do complicated algebra and logarithic equations, which I had never understood. I was fortunate to have the most amazing professor when I went back to earn my second bachelor’s before pursing my doctorate in audiology. I could not have made it through without her.

What kind of math did you take in high school?

I actually made it all the way to 7th grade before my teacher at the time recognized that I did not know how to do long division or fractions. I could usually solve the equations, but I had my own bizarre way of doing it. By the end of that year, I was able to do the math correctly, but I never considered myself a strong math student. I remember taking algebra, geometry, and trigonometry in high school, but I know I never really learned or understood any of it. I’m not sure how I managed to pass any of those classes. I remember taking a basic math class my first semester of college and being so glad that would be the last math class I would ever have to take. Little did I know I would go back to school years later and wind up doing more math than ever.

I still have a recurring nightmare about that college math class I took as a freshman. It’s the end of the semester, time for the final exam, and either I never went to the class or I did, but never learned anything, and now I have to take the exam!

Did you have to learn new skills in order to do the math you do at work?

I don’t think I had to learn new skills for the math I use day to day, but I definitely had to learn new skills in order to get through my grad school programs. I feel much more confident about my skills now than I did back in high school. Especially when it comes to algebra. I actually enjoy it, now that I know how to do it.

Thanks so much to Julie for visitin Math for Grownups today.  If you have questions for her, ask them in the comments section

Elizabeth Hanes, RN

Beth Hanes is a registered nurse in a plastic surgery center.  She takes care of patients before, during and after their surgeries.  Here’s how she uses math everyday.

What kind of math do you use in your job?

I use basic math for a lot of things, but probably the most important calculations are the ones related to medication use. Sometimes I dilute medication before giving it. For example, Promethazine needs to be diluted before it’s given in an IV. Using a 10mL syringe, I draw up 1mL of Promethazine and then add 9mL of normal saline (0.9% sodium chloride) to create a 10% Promethazine solution.

I also use basic math to determine, based on body weight, how much medication to administer. Medications are generally given on a milligram per kilogram basis. So, I convert a person’s weight in pounds to weight in kilograms (divide pounds by 2.2 to obtain kilograms), then I multiply this number of kilograms by the number of milligrams per kilogram to get the correct dosage. For example, Lidocaine might be ordered as 1mg/kg. A 220-pound patient weighs 100kg, so the correct dosage is be 100mg of Lidocaine.

How do you do your calculations?

I do use calculators because they’re typically faster, but I think it’s important to know how to do math by hand. I usually don’t have a calculator on hand in the operating room! Also, it’s critically important for me to have basic formulas memorized (such as how to convert pounds to kilograms). Without that knowledge, having a calculator or not is irrelevant.

Why is math important for your job?

Math skills help me ensure patient safety. There was a highly publicized case a few years ago in which actor Dennis Quaid’s infant twins were administered a very high dose of Heparin. This error occurred for many reasons, but one key factor was doing the math involved. This is a classic case of calculating dosage based on weight, and obviously errors were made in that calculation. In nursing, if you misplace a decimal point, you can kill someone.

When it comes to math in nursing, I think the main thing is to be very careful about calculations, double-check them, and then have someone else double-check them. No matter how good you may be at math, anyone can misplace a decimal point when calculating on-the-fly. It’s much better to take the extra seconds to have someone review your calculations and keep patients safe than to have any sense of ego about your math ability and endanger a patient.

What kind of math did you take in high school?

I had a rather sketchy math education, because my parents moved around a lot, and I only made it through Algebra II. On the other hand, advanced math was not yet common at the high school level when I was that age. Calculus, for example, was a college course. I did not feel I was good at math in high school. However, this “low math esteem” led me to focus on practicing real-world math skills.

These days, I am fairly comfortable with math, in general, though I frequently have to think through conversion problems, which are common in nursing. I find I often want to divide when I should multiply, for instance, so I have to be careful about that! Once I have a formula memorized, however, I feel very comfortable substituting variables with real values and arriving at the correct answer.

If you have questions for Beth, ask them in the comments section.  Oh, and today, June 20, is her birthday!  So take minute to wish her a happy day!

Read other Math at Work Monday entries in the archive.  And if you or someone you know wants to be interviewed for this regular, Monday feature, let me know.