\begin{exercice}
  Calculer.

  $A = \left| {2,4 - 0,8} \right| + \left| {7,38 + 0,5} \right| + \left| {1,2 -
      5,08} \right|$

  $B = \left| {\dfrac{1}{3} - \dfrac{2}{3}} \right| + \left| {\dfrac{2}{3} - 1}
  \right| - \left| {\dfrac{4}{3} - 1} \right|$
\end{exercice}