1.Easy
Practice exercise (made-up values, not clinical guidance). How many g of dextrose are in 50 mL of 50% w/v solution? Find m.
50% w/v50 mL
m = g
Pharmacy calculations worksheet with answers
2.Easy
A solution is 2% w/v. You need 90 mg of the drug. Draw up the volume in the syringe: what volume V is that?
2% w/v90 mg
V = mL
3.Medium
A solution has a ratio strength of 1:1000. You need 0.41 mg. Draw up the volume in the 1 mL syringe: what volume V is that?
1:10000.41 mg
V = mL
4.Medium
A solution has a ratio strength of 1:1000. You need 0.25 mg. Draw up the volume in the 1 mL syringe: what volume V is that?
1:10000.25 mg
V = mL
5.Hard
Practice exercise (made-up values, not clinical guidance). You must prepare 100 mL of 4% chlorhexidine from a 20% stock and purified water. How many mL V of water do you need? Round to the nearest whole mL.
20%0%4%100 mL
V = mL
6.Hard
A vial holds 250 mg of powder. You add 4.6 mL of diluent, and the powder adds 0.4 mL of volume. The prescription is 200 mg. Draw up the dose: what volume V do you give?
250 mg4.6 mL + 0.4 mL200 mg
V = mL
Answer key
- 1. m = 25 g
- 2. V = 4.5 mL
- 3. V = 0.41 mL
- 4. V = 0.25 mL
- 5. V = 80 mL
- 6. V = 4 mL
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