Numerous people, many of whom describe themselves (between gulps of Kool-Aid) as ‘fans of Derb,’ have written to say that the mathematical skills I displayed in an earlier post are distinctly fuzzy. If cookies today are 700 percent larger than their predecessors, those earlier cookies were, apparently, one-eighth the size of the original, not, as I stated, one-seventh. Frankly, I have no idea, but I never,ever , argue with ‘fans of Derb,’ so I stand corrected…