1.Easy
Practice exercise (made-up values, not clinical guidance). A solution of potassium permanganate has a ratio strength of 1:10 000. How many milligrams m are in 500 mL?
1:10 000500 mL
m = mg
Pharmacy calculations worksheet with answers
2.Easy
A solution is 1% w/v. You need 17 mg of the drug. Draw up the volume in the syringe: what volume V is that?
1% w/v17 mg
V = mL
3.Medium
A solution has a ratio strength of 1:1000. You need 0.11 mg. Draw up the volume in the 1 mL syringe: what volume V is that?
1:10000.11 mg
V = mL
4.Medium
A solution has a ratio strength of 1:1000. You need 0.71 mg. Draw up the volume in the 1 mL syringe: what volume V is that?
1:10000.71 mg
V = mL
5.Hard
A vial holds 2000 mg of powder. You add 9.2 mL of diluent, and the powder adds 0.8 mL of volume. The prescription is 680 mg. Draw up the dose: what volume V do you give?
2000 mg9.2 mL + 0.8 mL680 mg
V = mL
6.Hard
Practice exercise (made-up values, not clinical guidance). You must prepare 400 mL of 13% sodium chloride by mixing 23% and 3% sodium chloride. How many mL V of the 23% solution do you need? Round to the nearest whole mL.
23%3%13%400 mL
V = mL
Answer key
- 1. m = 50 mg
- 2. V = 1.7 mL
- 3. V = 0.11 mL
- 4. V = 0.71 mL
- 5. V = 3.4 mL
- 6. V = 200 mL
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