Slide-Rule Remedy To Numbers Desensitized Students

The rapid technological advancement of past decades changed significantly the way young engineers are educated these days. A large selection of numerical tools widely available on personal computers or pocket calculators is being applied where tables, nomograms or a slide rule were used in the past. It has been observed that despite of the gained time efficiency, high versatility and extreme precision, some students became largely affected through overuse of these tools and as a consequence became unable to verify obtained results by common sense and estimation. This paper presents once orthodox, currently unorthodox approach of using a highly customized circular-slide-rule and an associated simulator in electrical engineering courses in order to assist students develop a feel for what a sensible answer ought to be and thus help students to become less likely to make errors in the order of magnitude or false precision. This is because questioning a result in slide rule calculations is a necessary step leading to decimal point errors being de facto eliminated. By using the slide rule and practicing mental math to determine the result’s order of magnitude, students gradually become conscious of scales as well as become aware of precision and tolerance implications in engineering. Our slide rule can be customized in terms of a number of mathematical functions available plus the unused empty space can be populated by frequently used formulas or conversion tables specific to an individual subject area. Our slide rule was first applied in a classroom in 2007 with not so wide acceptance and reintroduced in 2011 with more positive results. A number of examples with classroom observations including a student feedback are presented.