Keys to Mathematical Treasure Chests: Classroom Slide Rules – Resources for Today’s Classrooms

Almost since slide rules disappeared from professional use, educators have considered ways to bring them back into mathematics classrooms. As with historical slide rules for student use, I have made no effort at a comprehensive listing of the resources available to instructors who are interested in how slide rules might “engage students in the visual experience of problem-solving, illustrate the connections between mathematics and real-life problems, and increase students’ appreciation for history” [Ackerberg-Hastings and Shell-Gellasch 2014, p. 9].

Introductory Overviews

The Reference Manual offered by the Oughtred Society may be the best single source for finding out what a slide rule is and does and learning about some of the major manufacturers [Davis and Hume 2012]. Just read carefully; by page 99 you may be tempted to become a collector yourself!

An illustrated self-guided course with 28 (brief) lessons and a link to an emulator is also available from the home page of the International Slide Rule Museum. Eric Marcotte’s chart of common scales was helpful to me when I was cataloguing the National Museum of American History’s over 200 slide rules.

How to Use a Slide Rule

If you or your students want to get started with slide rules more quickly than reading through a manual, short lessons that come up on search engines include a 1-pager by Liyen Liang of MIT and high school teacher Jay Ballauer’s Slide Rule Basics.

Do your students respond to videos? A training film from 1957 is available from the 16mm Educational Films channel on YouTube. More recently, a Professor Herning has recorded 65 videos on the general techniques of use and various specialized slide rules. Auto-generated closed captions and transcripts are available from both channels.

Online Emulators

The International Slide Rule Museum operates a free loaner program for instructors who are able to plan slide rule experiences in advance. Numerous virtual slide rules are available for immediate gratification, including 7 emulators at Derek’s Virtual Slide Rule Gallery and a collection of 43 replicas with downloadable code posted by Robert P. Wolf.

How to Make a Slide Rule

Printable templates for scales abound on the internet; several can be accessed through the International Slide Rule Museum’s Slide Rule Scales page or the General Information section of the Oughtred Society’s Links Library. In keeping with the spirit of this Mathematical Treasure Chest, Earl C. Rex explained in 1940 how to build a demonstration slide rule from lengths of baseboard [Rex 1940]. This article is available if your institution subscribes to the Wiley Online Library.

Classroom Use of Slide Rules

What might an instructor actually do with a class full of students and slide rules? In 2005 Paul R. Huff and Dagmar Rutzen both offered reports with teaching suggestions to the Journal of the Oughtred Society [Huff 2005; Rutzen 2005]. At a 2017 conference for earth educators, Victor Ricchezza of Georgia State University outlined a lab activity that uses slide rules to motivate skills for reading graphs, such as distinguishing between types of scales. He also provided files for 3D-printing slide rule bases. Richard Blake of STEMpunk offers an in-person and livestreamed presentation on “When Slide Rules Ruled,” but he has made many of the supporting materials available for free so others can use his efforts as a role model.