They are addressed as %MF, be careful though as they use the same address space as %MW
You also need to make sure you are reading them the right way round, if you are addressing them from SCADA or and HMI there is a usually setting for which way round the words are
Edit: so jst looked at your user name and question again and am putting 2 and 2 togetther and suspecting you are addressing from SCADA, in that case you just declare them as REAL and %MW in the SCADA app (thats if it allows native addressing which Citect does if you use Modnet30) or as its modbus address and the driver will take the n and n+1 address and know its a REAL