The ability to calculate drug doses accurately and quickly is an essential skill. This best-selling book uses a diagnostic test to pinpoint any weaknesses in the basic arithmetic required followed by specific exercises to remedy them. Examples are drawn from clinical practice, and explanations and graded exercises (with answers) cover the calculations required to administer tablets, mixtures and injections; to arrive at different drip rates; and to administer paediatric dosages safely. In this sixth edition, all drug usage material has been reviewed and updated reflecting recent changes in nursing practice.