Press green flag, then drag slider to the number you want to calculate the factorial of (don't put in the exclamation point). New system can calculate factorials well into the 2000! factorial range and likely very far beyond, due to revisions. However, since 3.0, new lag reduction systems as well as anti-crash mechanisms appear to greatly slow down the process by updating the screen unnecessarily, meaning larger numbers will take an incredibly long amount of time. 23! has 23 digits!
This project works by moving around scratch's 21 digit limit by storing digits in lists instead of variables. Numbers become to big to be stored in single digits around 106! and hit the 21 digit limit at 210!, so the highest full-format factorial that can be generated with this method is 209! (with 375 single digits and 21 digits in the final entry) By using a newer method, theoretically it can calculate the factorial of any number between 2 and 10^20, though in practice most numbers above 2000! will take way too long to be worth it (instead go to: https://www.calculatorsoup.com/calculators/discretemathematics/factorials.php) This system can be used in a variety of ways to store big numbers without exponents, although it does clutter up the JSON quite a bit. Digit milestones: 1! : 1 10! : 7 100! : 158 200! : 375 500!: 1135 1000! : 2568 2000! : 5736 (due to rate of digit calculation, I wouldn't suggest trying anything higher than this without 10+ minutes of AFK) 10000!: 35660 20000!: 213237 (if you tried this, I applaud you on wasting multiple hours/days on this project) 100000! : 456574 (If you're still reading, you probably have nothing better to do)