Reading scales can be difficult at first, but once you become used to the scales on one slide rule, you are pretty much set for reading scales on any slide rule.  Just looking at a slide rule it is plain to see that not all scales are calibrated the same, albeit some are very similar.  Even pocket slide rules are calibrated differently to the full-sized slide rules; they have to be because essentially the scale itself is half the size on the pocket rules as compared to the full-sized rules.

Care must be taken, whether beginner or expert, in reading the scales - it is very easy to misalign the cursor or another value.  This is something you do not want to do and proficiency comes by practice.  Misreading a scale can be costly and result in a very incorrect result!

As you know there are many scales for the slide rule and no slide rule has all the scales.  Some have up to 34 scales whereas others have maybe four scales.  The number of scales depends on the purpose of the slide rule.  There are even variations in the same scales, some are oversized giving more flexibility and some are the standard scalings.

In general, the scales are more detailed, that is, there are more calibrated marks at the beginning of the scale than at the end.  This of course varies with the inverse scales which have more calibrated marks at the right or the folded scales which have more calibrated marks towards the middle.

Whatever slide rule you use, it pays to familiarize yourself with the scales so that you can become confident in the use of your trusty slide rule.