I live in Washington state and I’m pretty certain the sales tax here is 10% (slightly higher than your maximum figure of 9.56%). It’s a pretty well known trick here that you can account for tax just by decimal shifting and adding (ex: 5.29$ without would be 5.29$ + 0.529$ ~= 5.81$ with tax). Is that 9.56% an “in practice” figure that accounts for rounding down? I’m curious where you read it.

I have mine set up with a bunch of categories that are sorted with a prepended 3-digit number. Allows me to have different sections of category without it getting mixed up. ex:

010 S
011 A+
012 A
013 A-
014 B+
etc...
350 plz play soon
355 wont play
...
800 dont remember buying this