0000 0001 0002 0003 0004 0005 0006 0007 0008 0009 0010 0011 0012 0013 0014 0015 0016 0017 0018 0019 0 + 0 + 1 + 9 = 10 (0 + 0) + 1 + 9 = 10 (0 + 0 + 1) + 9 = 10 (0 + 0) + (1 + 9) = 10 ((0 + 0) + 1) + 9 = 10 0 + (0 + 1) + 9 = 10 0 + (0 + 1 + 9) = 10 0 + (0 + (1 + 9)) = 10 0 + 0 + (1 + 9) = 10 0 - 0 + 1 + 9 = 10 (0 - 0) + 1 + 9 = 10 (0 - 0 + 1) + 9 = 10 (0 - 0) + (1 + 9) = 10 ((0 - 0) + 1) + 9 = 10