<a href="https://en.wikipedia.org/wiki/Slide_rule" class="extiw" title="w:Slide rule">w:Slide rule</a>, Pickett model N902-T simplex trig. This is a typical student model. The back has instructions for use and a table of fractional powers of 2, to the 64th, and their decimal equivalents.
<a href="//commons.wikimedia.org/wiki/User:ArnoldReinhold" title="User:ArnoldReinhold">ArnoldReinhold</a>
CC BY 2.5
<span class="int-own-work" lang="en">Own work</span> (I took this picture of an artifact in my possession on February 3, 2006. The object itself is functional in nature, was created before 1970 and has no copyright notice, either on front or back.)