Any way to correct the round off errors?

[G.S.]

Hello everyone,

When subtracting in Erlang: 0.92915-0.92945 we should get -0.0003 but Erlang
gives: -2.9999999999996696e-4   (when doing 92915-92945 Erlang gives -30 so
that's ok).

Anyway to make make it give -0.0003 ?, and in general make it give more
accurate answers?

Regards,
-Gene