All digits that are present in the minute fractions are taken into consideration in the calculation. GPS receivers emit sentences with differing lengths; 4 by Telit (ex. 5528.0453), 5 by u-blox (ex. 5528.02212). Other soruces indicate that 2 and 3 digits is also in use.
From a NMEA RMC sentence like $GNRMC,114922.00,A,5528.02212,N,00841.21015,E,0.315,,150916,,,A*6D
You would input the coordinate parts (comma index 3 to 6) 5528.02212,N,00841.21015,E.