N231 Posted Practice Math
1. A client is to receive dopamine 450 mg in 1000 mL D5W at 50 ml/hr. Calculate the dosage in
mcg/min. - ANS-375 mcg/min
Convert 450 mg 450,000 mcg (first shift decimal)
450,000 mcg/1000 mL x 50 mL/hr x 1hr/60 min = 375 mcg/min
\2. Calculate the number of grams of dextrose in 500 mL of D5W. The concentration is 5
grams/100 mL. - ANS-25 gm
5 gm : 100 mL :: X gm : 500 mL = X gm (ratio & proportion) 5 gm / 100 mL x X gm / 500mL = 25
gm 100X = 5x500
X = 2500/100 X= 25 gm
\3. The prescriber ordered drug "X", 500 mg by mouth, twice a day. Each tablet contains 200
mg. How many tablets will the nurse administer per dose? - ANS-2.5 or 2 ½ tabs /dose
500mg/200 mg x 1 tablet = 2.5 or 2 ½ tabs /dose (Desired/Have x Quantity)
\4. An IV of 500 mL D5W is infusing at a rate of 20 gtt/min. How many hours and minutes will it
take to finish if the drop factor is 10 gtt/ml? - ANS-4 hrs 10 min
500 ml x 10 gtt/1 ml x 1 min/20 gtt = 250 min 250 min x 1 hr/60 min = 4.16666667 hrs
(0.16666667 is an hour fraction) 0.16666667 hrs x 60 min/hr = 10 min ans. = 4 hrs 10 min
\5. The nurse is to administer Atropine gr. 1/60. How many milligrams will the client receive? -
ANS-1 mg
60 mg : gr 1 :: X mg : 1/60 gr (must know the conversion factor) 60 mg /gr 1 =X mg /gr1/60 X=
60 x 1/60 X = 1 mg
\6. The provider orders levothyroxine 0.075 mg by mouth every morning on an empty stomach.
The medication is available as scored tablets of 50 mcg. How many tablets should the nurse
administer? - ANS-1.5 tabs
0.075 mg = 75 mcg (shift decimal first) 75 mcg/50 mcg x 1 tab = 1.5 tabs (D/H xQ)
\7. The nurse is to administer Clindamycin 0.6 g I M every 6 hours. The drug is available in a 4
mL vial labeled 250 mg per mL. How many mL should be administered per dose? - ANS-2.4 mL
0.6 g = 600 mg (shift decimal) 600mg/250 mg x 1 ml = 2.4 mL (D/H xQ)
\8. A 48.4 lb child has an ordered for 125 mg of an antibiotic medication by mouth every 6
hours. The oral suspension is available as 120 mg per 10 mL. The recommended dose is 15 mg
to 40 mg /kg /day. What is the dosage range daily for this child? Is this order safe? (two answers
required) - ANS-Range 330 mg/day to 880 mg/day
Yes, safe
24 hr/6 hr = 4 times /day (ordered dosage per day) 125 mg/dose x 4 dose/day = 500 mg/day
(milligrams dose ordered per day) 1/day x 15 mg/kg x 1Kg/2.2lb x 48.4 lb/1= 330 mg/day (min
1. A client is to receive dopamine 450 mg in 1000 mL D5W at 50 ml/hr. Calculate the dosage in
mcg/min. - ANS-375 mcg/min
Convert 450 mg 450,000 mcg (first shift decimal)
450,000 mcg/1000 mL x 50 mL/hr x 1hr/60 min = 375 mcg/min
\2. Calculate the number of grams of dextrose in 500 mL of D5W. The concentration is 5
grams/100 mL. - ANS-25 gm
5 gm : 100 mL :: X gm : 500 mL = X gm (ratio & proportion) 5 gm / 100 mL x X gm / 500mL = 25
gm 100X = 5x500
X = 2500/100 X= 25 gm
\3. The prescriber ordered drug "X", 500 mg by mouth, twice a day. Each tablet contains 200
mg. How many tablets will the nurse administer per dose? - ANS-2.5 or 2 ½ tabs /dose
500mg/200 mg x 1 tablet = 2.5 or 2 ½ tabs /dose (Desired/Have x Quantity)
\4. An IV of 500 mL D5W is infusing at a rate of 20 gtt/min. How many hours and minutes will it
take to finish if the drop factor is 10 gtt/ml? - ANS-4 hrs 10 min
500 ml x 10 gtt/1 ml x 1 min/20 gtt = 250 min 250 min x 1 hr/60 min = 4.16666667 hrs
(0.16666667 is an hour fraction) 0.16666667 hrs x 60 min/hr = 10 min ans. = 4 hrs 10 min
\5. The nurse is to administer Atropine gr. 1/60. How many milligrams will the client receive? -
ANS-1 mg
60 mg : gr 1 :: X mg : 1/60 gr (must know the conversion factor) 60 mg /gr 1 =X mg /gr1/60 X=
60 x 1/60 X = 1 mg
\6. The provider orders levothyroxine 0.075 mg by mouth every morning on an empty stomach.
The medication is available as scored tablets of 50 mcg. How many tablets should the nurse
administer? - ANS-1.5 tabs
0.075 mg = 75 mcg (shift decimal first) 75 mcg/50 mcg x 1 tab = 1.5 tabs (D/H xQ)
\7. The nurse is to administer Clindamycin 0.6 g I M every 6 hours. The drug is available in a 4
mL vial labeled 250 mg per mL. How many mL should be administered per dose? - ANS-2.4 mL
0.6 g = 600 mg (shift decimal) 600mg/250 mg x 1 ml = 2.4 mL (D/H xQ)
\8. A 48.4 lb child has an ordered for 125 mg of an antibiotic medication by mouth every 6
hours. The oral suspension is available as 120 mg per 10 mL. The recommended dose is 15 mg
to 40 mg /kg /day. What is the dosage range daily for this child? Is this order safe? (two answers
required) - ANS-Range 330 mg/day to 880 mg/day
Yes, safe
24 hr/6 hr = 4 times /day (ordered dosage per day) 125 mg/dose x 4 dose/day = 500 mg/day
(milligrams dose ordered per day) 1/day x 15 mg/kg x 1Kg/2.2lb x 48.4 lb/1= 330 mg/day (min
