If you are using VisualC the code
float f=1212.122f;
will give you 1212.12 in the watch window (also rounds string conversion to 6 digits) and prints 1212.121948 using printf("f=%f\n",f); so I don't quite see why you are getting so cross.
float f=1212.122f;
will give you 1212.12 in the watch window (also rounds string conversion to 6 digits) and prints 1212.121948 using printf("f=%f\n",f); so I don't quite see why you are getting so cross.