Question 1

A nurse measured the circumference of an edematous leg and documented "15.5 inches at mid-calf, left leg" on the client's electronic medical record. For comparison, she measured the right calf and documented "12 inches at mid-calf, right leg." The left calf is what percent larger than the right calf?

Accepted Answer

This is a multiple-step problem. To estimate the difference between the measurements of the left calf compared to the right calf, subtract 12 inches from 15.5 inches, which equals 3.5 inches. To determine the percent, create a fraction by dividing the difference (3.5 inches) by the largest or total number (15.5 inches). Clear the decimal points before final division. Divide: 3.5/15.5 = 7/31. To change a fraction into a decimal, divide the numerator by the denominator. Add decimal points in the dividend and quotient as needed: 7/31 = 0.225. Carry out to the hundredths place. To round off a decimal, the final number is dropped. When the final number is 5 or greater, drop that number and increase the adjacent number by 1. Therefore, 0.225 = 0.23. Next, change the decimal to a percent by moving the decimal point two places to the right, then write the percent sign: 0.23 = 23%.

Question 2

The physician prescribed taking blood pressure assessments on a patient, lying and standing, every 4 hours, for 24 hours. Determine the percentage difference between the first two systolic readings (140 mm Hg lying and 125 mm Hg standing).

Accepted Answer

To estimate the difference between the two systolic readings (140 mm Hg lying and 125 mm Hg standing), subtract 125 mm Hg from 140 mm Hg. To determine the percent, create a fraction by dividing the difference (15 mm Hg) by the larger number or total (140 mm Hg). Divide: 15/140 = 3/28. To change a fraction into a decimal, divide the numerator by the denominator. Add decimal points in the dividend and quotient as needed: 3/28 = 0.107. Carry out to the hundredths place. To round off a decimal, the final number is dropped. When the final number is 5 or greater, drop the number and increase the adjacent number by 1. Therefore, 0.107 = 0.11. Next, change the decimal to a percent by moving the decimal point two places to the right, then write the percent sign: 0.11 = 11%.

Question 3

A physician prescribed an IV solution, 500 mL of 0.9% NS with 25 g of an antibiotic, to run over 8 hours. What percent of the IV fluids would be given each hour?

Accepted Answer

To estimate what percent of the IV fluid is given each hour, first determine the amount of IV solution that would be given hourly: divide 500 mL/8 hours = 62.5 mL/hour. Next, divide the hourly amount by the total amount = 62.5/500 = 0.125 mL/hour/500 mL. Change the decimal to a percent by moving the decimal point two places to the right and then writing the percent sign. Therefore, 0.125 = 12.5%.

Question 4

A physician prescribed 35 mg of a medication, IM, q4h, prn. The drug is available as 50 mg/mL. How many milliliters would the nurse give for each dose? If the patient/client received six doses over 24 hours, how many total milliliters would the nurse give?

Accepted Answer

When the amount of drug prescribed is different from the supply, you can solve the dosage problem with proportion, either using ratios or fractions. When one of the numbers is unknown, the letter x substitutes for the missing number. Proportion (Ratios): 1 mL : 50 mg :: x mL : 35 mg; 50x = 35/50 = 0.7 mL. Proportion (Fractions): 1 mL/50 mg = x mL/ 35 mg; 50x = 35/50 = 0.7 mL. To estimate the total milliliters given over 24 hours, multiply 0.7 mL×
6 doses (24 hours ÷ 4 hours) = 4.2 mL.

Question 5

The physician ordered 20 mg of a drug by IV push, to be given over 5 minutes, q12h. The medication is available as 25 mg/5 mL. How many milliliters would the nurse give for each dose? How many milliliters of medication would be given over each minute?

Accepted Answer

When the amount of drug prescribed is different from the supply, you can solve the dosage problem with proportion, either using ratios or fractions. When one of the numbers is unknown, the letter x substitutes for the missing number. Proportion (Ratios): 5 mL : 25 mg :: x mL : 20 mg; 25x = 100/25 = 4 mL. Proportion (Fractions): 5 mL/25 mg = x mL/20 mg; 25x = 100/25 = 4 mL. To estimate the milliliters given over each minute, divide the total milliliters by the total minutes (4 ÷ 5 = 0.8 mL/minute).

Question 6

An elderly patient/client takes her morning medications with 4 ounces of Boost. The doctor wants her to increase her Boost intake by 50%. How many additional ounces would the patient/client take with her morning dose of medications? Use the decimal format to estimate the percent increase.

Accepted Answer

Percent means "parts per hundred." Percent is a fraction, containing a variable numerator and a denominator that always equals 100. Therefore, 50% = 50/100 (fraction), 50:100 (ratio), and 0.5 (decimal). To determine the additional Boost® the patient/client should drink, multiply 50%×
4 oz. Using the decimal format (0.5×
4), line up the numbers on the right. Do not align the decimal points. Starting at the right, multiply each digit in the top number by each digit in the bottom number, just as is done with whole numbers. Add the products. Place the decimal point in the answer by starting at the right and moving the point the same number of places that you totaled earlier. The answer is that the patient/client would take 2 additional ounces of Boost® with her medications.

Question 7

The physician prescribed 60 mg of Klonopin (clonazepam) available as a 40 mg scored tablet. The patient/client was advised to take how many tablets for each dose? Use Proportion (Ratios and Fractions) to solve this problem.

Accepted Answer

When the amount of drug prescribed is different from the supply, you can solve the dosage problem with proportion, either using ratios or fractions. When one of the numbers is unknown, the letter x substitutes for the missing number. Proportion (Ratios): 1 tab : 40 mg :: x tab : 60 mg; 40x = 60/40 = 1.5 tablets. Proportion (Fractions): 60 mg/40 mg = x /1 tab; 40x = 60/40 = 1.5 tablets.

Question 8

A patient/client takes 0.125 mg of a medication, three times daily. How many milligrams would the patient/client take in four days?

Accepted Answer

First determine the total amount of medication taken in one day. Multiply 0.125 mg x 3 times per day. To multiply a decimal (0.125) by a whole number (3), place the decimal point in the answer by starting at the right and moving the decimal point the same number of places equal to the sum of the decimal points. Therefore, 0.125 mg x 3 = 0.375 mg ( the decimal point in the answer is moved three points to the left). This is the amount of medication in one day. Then multiply 0.375 mg x 4 days = 1500. Move the decimal point three places to the left; 1500 = 1.5 mg.

Question 9

A patient/client in a nursing home is weighed weekly. Her initial weight on admission was 174 ½ pounds. After three weeks, she weighed 156 ¼ pounds. How many pounds did the patient/client lose in three weeks? Subtract the mixed numbers after determining the least common denominator (LCD).

Accepted Answer

Subtract the patient/client's current weight (156 ¼) from her initial weight (174 ½). To subtract mixed numbers, one method is to find the least common denominator (LCD) for ½ and ¼ and leave the fractions as mixed numbers. For 2 and 4, the LCD = 4. Rewrite each fraction using the LCD; divide the LCD by the denominator of each fraction and then multiply that result by the numerator of the fraction. After conversion of the fractions (174 2/4 -156 ¼ ), the numerators of the fractions are subtracted and the whole numbers are subtracted = 18 ¼ .

Question 10

A diabetic patient/client was prescribed an 1800 calorie ADA diet. The patient/client can have 35% of her calories (630) in the form of carbohydrate (CHO). To maintain this same ratio, how many carbohydrate calories would she be allowed if the ADA diet was reduced to 1500 calories? Use a proportion (ratios) to solve the problem.

Accepted Answer

A ratio indicates the relationship between two numbers. A proportion is the relationship between two ratios. When one of the numbers in the proportion is unknown, the letter x substitutes for that number. Set up the ratio/proportion: 630 CHO calories: 1800 ADA calories = x CHO calories : 1500 ADA calories; 1800 x = 630 × 1500/1800; x = 945,000/1800 = 525 CHO calories.

Quiz 1: Arithmetic Needed for Dosage

The physician prescribed taking blood pressure assessments on a patient, lying and standing, every 4 hours, for 24 hours. Determine the percentage difference between the first two systolic readings (140 mm Hg lying and 125 mm Hg standing) .