Mathematics. One word that strikes terror into 99% of all household pupils and promotes what I always call 'number shock' - that moment when you look at the sums on the page and... nothing, your brain goes blank, your heart goes into overdrive and all you can think about is how you are going to get the earth to swallow you up so you can escape.

When I took my O Levels, we didn't have computers at school - we didn't even have calculators to use. We had our fingers of course, but, they were only good for counting in tens and twiddling with.

I used to just hate those problems that were set in an everyday situation, where you had to find the numerical answer. For instance, that old classic that went "A space-ship from Mars containing 50 small demons landed on earth. 45 of them had horns and 23 had tails but 3 of them had no horns and no tail. How many had horns and tails?"

The answer is 'who cares anyway!', but knowing you have to work it out you dutifully set to it.

Sets is a suite of programs designed to help you understand basic maths ideas and help you solve problems similar to the above example. The ideas are based on the set theory of mathematics - an algebraic system using a series of circles and ovals called Venn diagrams (named after the English mathematician John Venn).

Venn diagrams are very useful for illustrating how sets of numbers are related to one another and the Spectrum's graphic capabilities are perfect for this type of demonstration.

The manual is very thorough and takes you slowly through the Venn system, starting with very simple examples and then gradually increasing the difficulty level, whilst always making sure you are still understanding the principles. One thing I liked about this program is its insistence than you try to work out the problems on your own first, using your own brain before the computers; so you're not totally dependent on the machine for your answers.

When you load up, you get a six-choice menu which takes you into each section of the Set system, from the initial setting of the co-ordinates and shading of the Venn diagrams, through to element placing and solving. It may sound complicated but if you follow the manual closely, it is blissfully easy.

One criticism I do have, is that there are three maths symbols that have to be used and the manual fails to tell you which key promotes which symbol on screen. I hope this is just an oversight on the printing and not the authors' assuming the user should know as this is not in keeping with the way the manual has been written.

This aside, the program is concise and error free and for once I can sleep easy, safe in the knowledge that only 21 demons had both horns and a tail. I worked it out and I solved it using Sets. Not bad huh?

Label: Alpha Plus

Author: J Andrews, A McMaster

Memory: 48K/128K

Reviewer: Andy Moss

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Example of the system showing Venn diagrams. In this case Set B is a part of Set A (on the right).