Aaaah ok, got it! I was tying knots in my brain 
Mmm it looks like something we could improve on our side. I’ll share with the team.
In the meantime, something like this should work:
Here’s the Javascript equivalent if you prefer that approach:
return (Math.round(number * 100) / 100).toFixed(2)
Just make sure you replace the number parameter by whatever variable or item data you are getting your number from.
So for example in my project, I’m using the custom formula I created in no-code above and binding it to my item data coming from a Xano collection:
