There has been much discussion over what scales should be present on a slide rule for the beginner.  Some say that there should be a minimum of scales so as not to distract the new user and others say that the more elaborate rules should be use because they will encourage curiosity.

In reality, it comes down to a person's preference.  There are those who like the simple rules and those who love to have as many scales as possible, even though they may never use them.  However, for the beginner, there should be enough scales so that efficient techniques can be demonstrated and taught.

Even though there are many types of calculations which can be performed with the minimum of scales, often the same or similar calculations can be simplified and performed faster and more efficiently by the addition of another scale or two.

It is my view that a good beginner's slide rule should have the following scales consisting of K, A, B, C, CF, CI, DF, D.  With these scales, the learner slide ruler has ample to work with and can later move on to a more complex rule if required. 

Tim Van Dusen has produced what he calls the Kid's Rule which consists of the A, B, CI, C and D scales.  This rule is ideal for those kids wanted to start learning how to use the slide rule ... it's also suitable for those big kids too.

Nevertheless, to learn how to use a slide rule, all you need is any slide rule.

The fun and intrigue will still be the same!

I would like to thank Mark Armbrust for his careful proof-reading of my work and offering a number of useful suggestions.