[ebingdom]

I wonder why they don't just use the highest precision possible given whatever representation of numbers they're using? I know these extra digits would be unlikely to ever matter in practice, but why even bother truncating more than necessary by the hardware? (Or do they not use hardware to do arithmetic calculations?)

[OscarCunningham]

They do. This is precisely the number of accurate digits you get when you use a double (i.e. 64 bit floating point). https://float.exposed/0x400921fb54442d18