Nursing Mathematics
UNDERSTANDING UNITS &
CONVERSIONS
Quantity
Acceptable Units
VOLUME - the amount of fluid that a container holds
Liters (L), Milliliters (mL)
MASS – weight of an object
Kilogram (kg), Milligrams (mg), Micrograms (mcg)
RATE OF INFUSION
mL/hr
TIME OF INFUSION
Hours (hr), minutes (min)
Concentration
mg/mL
1 L = 1000 mL
1 kg = 1000 g
1 hr = 60 min
Examples:
4 L = ______ mL
4 L x 1000 mL = 4000 mL
1L
1 L = 1000 cc
1 g = 1000 mg
1 mg = 1000 mcg
230 mL = ______ L
4.5 g = _____ mg
230 mL x
4.5 g x 1000 mg = 4500 mL
1g
1 L = 0.23 L
1000m L
0.23
0
1000)230.00
- 00
2300
- 2000
3000
- 3000
0
45
x 1000
45000
So 4.5 x 1000 = 4500.0
Practice:
Question
Set up
Operation
Final Answer
0.5 g = _____ mg
0.5 g x 1000 mg =
1g
248 mg = _____ g
248 mg x
1g
=
1000 mg
5

x 1000
5000
0.248 0
1000)248.000
- 0
2480
- 2000
4800
- 4000
8000
- 8000
0
40 mcg = ______ mg
4 mcg x
1 mg
=
1000 mcg
500 mL = _____ L
500 mL x
1L =
1000mL
300 g = ______ kg
300 g x
1 kg =
1000 g
8.3 L = ______ mL
8.3 L x 1000 mL =
1L
125 mL = _____ mL
hr
min
125 mL x 1 hr =
hr
60min
3.2 hr = __hr__ min
3.2 hr = 3hr+ 0.20 hr
0.2 hr x 60 min =
1 hr
0.5
x 1000
500.0
0.248 g
0.04 0
1000)40.00
- 0
400
- 0
4000
- 4000
0
0.5
0
1000)500.0
- 0
5000
- 5000
0
0.3
0
1000)300.0
- 0
3000
- 3000
0
0.04 mg
0.5 L
0.3 kg
83

x 1000
83000
2.0833… 0
60)125.00000
- 120
50
- 0
500
- 480
200
- 180
200
- 180
200…
x
2
60
120
500 mg
8.3
x 1000
8300.0
8300 mL
2.083 mL
min

x
0.2
60
12.0
3hr 12min
Now try these:
Question
Set up
Operation
Final Answer
1.5 g = _____ mg
1500 mg
25 mg = _____ g
0.025 mg
25 mcg = _____ mg
0.025 mcg
60 mL = _____ L
0.06 L
4.3 kg = _____ g
4300 g
0.015 L = ______mL
15 mL
250 mL = _____ mL
hr
min
4.167 mL
min
4.3 hr = __hr__ min
4 hr 18 min