#   Value   Residue    Rounded     Comment
1    10.3     0.0        10        0.3 is added to the residue
2    10.3     0.3        11        10.3 + 0.3 = 10.6, which rounds to 11 with -0.4 residue
3    10.4    -0.4        10        
     ====               ====
     31.0                31