Thanks for the heads up! While the Numscript backend itself uses big.Int, we're still using normal javascript numbers in the playground for now so that's where it's coming from. But we should definitely switch to BigInt in the playground code though and that would solve the issue.

You should never use floats for money. In python Decimal works well. TigerBeatle uses 128 bit accounts and amounts which I thought was interesting although more than needed gor many cases.