Linux 加，减，乘，除

#!/bin/bash

num1=10
num2=2

#两个数相加
add=$[$num1+$num2]
echo $num1 + $num2 '=' $add

#两个数相减
sub=$[$num1-$num2]
echo $num1 - $num2 '=' $sub

#两个数相乘
mut=$[$num1*$num2]
echo $num1 '*' $num2 '=' $mut

#两个数相除
div=$[$num1/$num2]
echo $num1 / $num2 '=' $div

#固定值
temp=$[$num1*10]
echo $num1 '*' 10 '=' $temp