===== Per Package Inventory =====
Some people collect whistles in various boxes and bags of a certain amount. They'll produce whistles until they collect a bag of 500. This requires you to keep track of whistles in a certain package, but you really only have that one package to track. Use a sticky note, make a text file on your computer or phone, just track it somehow. Then, when you end up with 5 bags of whistles, you'll know you have 2500 whistles.

One printable helper that may help is [[https://makerworld.com/en/models/2255468-whistle-counting-tray-for-micro-bitonal-whistles#profileId-2456819|Whistle Counting Tray for Micro Bitonal Whistles]] by [[https://makerworld.com/en/@thebrokencircle|The Broken Circle]] if you use that particular whistle model.