echo
echo '================ Values: ================'
echo
echo -e "Enter first value: c"
read -r a
echo -e "Enter second value: c"
read -r b
echo
echo '================ Menu: ================'
echo
echo "1. Value addidtion"
echo "2. Value multiplition"
echo "3. Value division"
echo "4. Value subtraction"
echo "5. Value modules"
echo
echo -e "Enter your choice: c"
read -r evalres
case $evalres in
1) echo "$a + $b = `bc <<< "scale=1; $a + $b"`";;
2) echo "$a * $b = `bc <<< "scale=2; $a * $b"`";;
3) echo "$a / $b = `bc <<< "scale=2; $a / $b"`";;
4) echo "$a - $b = `bc <<< "scale=1; $a - $b"`";;
5) echo "$a % $b = `bc <<< "scale=2; $a % $b"`";;
*) echo "invalid option selected.";;
esac