#!/bin/bashecholet a=11            # Same as 'a=11'let a=a+5           # Equivalent to  let "a = a + 5"                    # (Double quotes and spaces make it more readable.)echo "11 + 5 = $a"  # 16let "a <<= 3"       # Equivalent to  let "a = a << 3"echo "\"\$a\" (=16) left-shifted 3 places = $a"                    # 128let "a /= 4"        # Equivalent to  let "a = a / 4"echo "128 / 4 = $a" # 32let "a -= 5"        # Equivalent to  let "a = a - 5"echo "32 - 5 = $a"  # 27let "a *=  10"      # Equivalent to  let "a = a * 10"echo "27 * 10 = $a" # 270let "a %= 8"        # Equivalent to  let "a = a % 8"echo "270 modulo 8 = $a  (270 / 8 = 33, remainder $a)"                    # 6echoexit 0