Rounding for mass on engines

I'm not sure if I saw it anywhere in the Fleet Book, but when I ran the
calculations on existing designs, I think I figured it out, but I wanted
to
double check...

When determining the size of Main Engines and FTL Drive, do you round
down
less than 0.5 and round up 0.5 or greater?

For instance, a ship of Mass 14 requires an FTL drive which is 10% Mass.
This is 1.4...Rounded down to 1? This same ship requires a Thrust of 6,
which is 5% of Mass per Thrust, which is 4.2.... Rounded down to 4?

Thanks,
Christopher