English: The left end of a Keuffel & Esser Deci-Lon slide rule, with a thin blue line added to show the values on the S, T, and SRT scales corresponding to sine and tangent values of 0.1 and 0.01. The S scale shows arcsine(0.1) = 5.74 degrees; the T scale shows arctangent(0.1) = 5.71 degrees; the SRT scale shows arcsine(0.01) = arctangent(0.01) = 0.01*180/pi = 0.573 degrees (to within "slide rule accuracy"). At the right end of the SRT scale (not shown), the value is 5.73 degrees, indicating that this SRT scale is calibrated to radians, and is off by nearly 0.4% for the tangent and 0.2% for the sine for angles around 5 degrees. Some ST scales are calibrated to balance the sine and tangent errors.