\[\boxed{\mathbf{4.}\mathbf{64}}\]
\[\textbf{а)}\ | - 21,5| = 21,5\]
\[\textbf{б)}\ |21,5| = 21,5\]
\[\textbf{в)}\ | - 33| = 33\]
\[\textbf{г)}\ \left| - \frac{1}{3} \right| = \frac{1}{3}\]
\[\textbf{д)}\ \left| 4\frac{7}{9} \right| = 4\frac{7}{9}\]
\[\textbf{е)}\ \left| - 5\frac{19}{20} \right| = 5\frac{19}{20}\]