\[\boxed{\mathbf{26.}}\]
\[37 + 3 = 40\]
\[37 - 3 = 34\]
\[37 + 13 = 50\]
\[37 - 13 = 24\]
\[48 + 2 = 50\]
\[48 - 2 = 46\]
\[48 + 32 = 80\]
\[48 - 32 = 16\]
\[56 + 4 = 60\]
\[56 - 4 = 52\]
\[56 + 44 = 100\]
\[56 - 44 = 12\]
\[75 + 5 = 80\]
\[75 - 5 = 70\]
\[75 + 25 = 100\]
\[75 - 25 = 50\]