打开一个终端，输入bc

1 $ bc

打开bc，bc可以实现简单的数学计算

一般不懂的软件都是先使用-h 或者--help来查询软件使用帮助

$ bc -h
usage: bc [options] [file ...]
  -h  --help         print this usage and exit
  -i  --interactive  force interactive mode
  -l  --mathlib      use the predefined math routines
  -q  --quiet        don't print initial banner
  -s  --standard     non-standard bc constructs are errors
  -w  --warn         warn about non-standard bc constructs
  -v  --version      print version information and exit

进入bc后输入表达式回车就可以得到计算结果，输入quit退出

$ bc
bc 1.07.1
Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006, 2008, 2012-2017 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'. 
5+5
10
22+10
32
quit
$