echo " $((2+3))"

#! /bin/bash 
number1=10
number2=20

echo " SUM $((number1 + number2)) "
echo " PRODUCT $((number1 * number2)) "
echo " DIVISION $((number1 / number2)) "
echo " REMINDER $((10 % 3)) "
echo " POWER $((3 ** 2)) "

echo "*-------------------------*"
echo " Increase A Variable "

number1=$((number1 + 1))
echo " Variable now is $number1"

echo "*-------------------------*"
# another way to set variable 
echo " making variable $number2 "
echo " $(( number2++ )) " #print the variable 
echo " $(( ++number2 )) " #increase number before printing
echo " another variable is $number2 "

echo "*-------------------------*"
number3=30
number3=$((number3 + 3))
echo " value = $number3"

echo " add: $(( number3 += 3 )) "
echo " $number3 "

echo "*-------------------------*"
echo " substract: $(( number3-=10 )) "
echo " $number3 "

echo "*-------------------------*"
echo " multiply: $(( number3*=10 )) "
echo " $number3 "