Comando bc: Calculadora con Linux

[root@LINUX1 ~]# echo 5+8
5+8
[root@LINUX1 ~]# echo 5+8|bc
13
[root@LINUX1 ~]# echo "(5+8) * 7"|bc
91
[root@LINUX1 ~]# echo "(5+8) * 7 + 0.5"|bc
91.5