It will be no surprise to learn that Walker Runn has bumbled himself into a corner. Bias in a measurement system is the difference between the actual measurements taken, and the true value (often called "reference") of what is being measured.
An easier way to determine this is to simply click a few keys on GAGEpack and then show the printout to the auditor. In this case, I used data from page 87 of the MSA book, with a bias of .0067. GAGEpack shows this in scientific notation 6.66666 E - .03.