string manipulation and float math problems

Well this works.....basically just got rid of that divide by 100. It looks like this now. Anything that I should be worried about doing it this way?

 //cconvert longitude to GPS decimal format
    f = atof(longit1);
    Serial.println(longit1);
    longdegrees = (int)(f/100); //isolate degrees
    Serial.println(longdegrees);
    longminutes = (f - (longdegrees*100)) + atof(longit2)/10000.00;
    Serial.println(longit2);
    Serial.println(longminutes,6);
    longdecCoords = long((longminutes / 60.0)*1000000UL);
    if(EW[0] == 'W') longdegrees *= -1.0;