But You Don't Have To Understand Math.

I know some of you have ad blockers running on your web btrowser, but you really shouldn't.  You're missing all the fun.  I just saw an ad for something that will help you avoid  "3 Awful Guitar Mistakes."  Apparently that something doesn't involve math, as the ad copy states "If you do either of these 3 things yo will NEVER play guitar well."  Of course maybe I was wrong in assuming that you can't use the term either when there are more than two choices.  Number things have never been my strong suit.