1. To show the students the range of calculations that they are expected to know

2. To provide help in those areas that students have commonly found problematical.

A screen from one of the activity modules

Subject 1: SI Units and Terminology
This is a basic subject introducing the student to the series of prefixes used for SI Units e.g. kilo-, deci-, nano- etc., the units which are used for measuring length, mass, temperature and volume and some of the terminology that the students might encounter. The subject consists of five activities: SI Units: Length, SI Units: Mass, SI Units: Temperature, SI Units: Volume, and Terminology.

Subject 2: Percentages
This subject introduces the student to ways of expressing concentration using percentages. Each activity shows the student a definition, uses of the concentration expression, how to prepare a solution of known concentration and an equation which can be used for calculations. The activity then gives example calculations and allows the student to practise questions. Two methods for solving the questions are shown: the first uses the equation itself, the second works from the definition and uses ratios more. The subject consists of four activities: What are Percentages? Percent Weight in Volume, Percent Weight in Weight, and Percent Volume in Volume.

Subject 3: Moles, Molarity etc.
This subject introduces the student to ways to express concentration using moles. The activities - where appropriate - show the student how to prepare a solution of known concentration and an equation which can be used for calculations The activities then show example calculations and allow the student to practise questions. The subject consists of four activities: Moles and RMM, Molarity, Mole Fraction, and Molality.

Subject 4: Other Ways to Express Concentration
This subject looks at three other ways to express concentration other than those covered in the previous subjects.The subject consists of three activities: Parts Components, Solubility Expressions, and Normality and Equivalence.

Subject 5: Conversion Between Concentrations
This subject contains a single activity called Test. The activity has no explanation and consists only of sets of questions testing whether the student can convert between the various ways to express concentration.

Subject 6: Chemical Yields
This subject has only one activity called Calculating Chemical Yields. In this activity, the student can find out how to calculate the theoretical yield of a reaction, the percentage yield of a reaction and the minimum amount of reactant needed to produce a specified amount of product.

Subject 7: Pharmacy Practice Calculations
This subject covers some of the calculations that the student should be able to do if the student is to dispense chemicals correctly. There are six activities: Increasing/Decreasing Formulae, Number of Doses, General Dilutions (covering dilution of liquids and of solids), Using Stock Solutions (including Ethanol and Formaldehyde solutions), Alligation, and Least Weighable Amount/Percentage Error.

Many of the activities within the package follow a similar structure:

First, the student is given a brief introduction to the topic:
For example in the topics on concentration, the student is given a definition of the concentration expression, told for what the concentration expression is used, how to prepare a solution etc. of a particular concentration and finally some of the problems that the student should be aware of when using that particular way of expressing concentration.

The student is then shown an equation that can be used for calculations:
Wherever possible, the student is shown how to derive the equation - often by using the definition given in the introduction.

For three-part equations the student then looks at how to calculate each part of the equation:
For each part of the equation the student follows an example calculation and can then have a go at some practice questions.

Finally, each activity finishes with a set of mixed questions:
These questions cover all the types of calculation covered in the activity and the questions are often harder and require the student to approach the problem in a slightly different way.