\[\boxed{\mathbf{40.}}\]
\[\textbf{а)}\ 67 + 3 = 70\]
\[40 - 1 = 39\]
\[58 - 4 = 54\]
\[37 + 32 = 69\]
\[56 - 23 = 33\]
\[64 - 14 = 50\]
\[\textbf{б)}\ 56 + 4 - 40 = 60 - 40 = 20\]
\[100 - 1 - 35 = 99 - 35 = 64\]
\[100 - 70 + 47 = 30 + 47 = 77\]
\[60 - 0 - 1 = 60 - 1 = 59\]
\[34 + (0 + 6) = 34 + 6 = 40\]
\[73 + (27 + 0) = 73 + 27 = 100\]