#!/bin/bash
let "a = 10"
let "b = 2"
let "c = a+b"
echo $c
let "e = 10*2"
echo $e
let "f = 15"
let "f *=2"
echo $f
echo " "
let 'var = 5 + 5'
echo "$var"
echo " "
echo $(( 20 + 20 ))
var1="2"
var2="5"
echo $(( $var2 % $var1 ))