Make a Mathematics Calculator in Linux Shell Scripts

echo "Enter The First Number:->";
read no1
echo "Enter The Second Number:->";
read no2


echo "1:Addition";
echo "2:Substraction";
echo "3:Multiplication";]
echo "4:Division";

echo "Please Select Above Option:->";
read c

case $c in

    1)
        echo "Addition is:->" `expr $no1 + $no2`;
        ;;
    2)
        echo "Substraction is:->" `expr $no1 - $no2`;
        ;;
    3)
        echo "Multiplication is:->" `expr $no1 \* $no2`;
        ;;
    4)
        echo "Division is:->" `expr $no1 + $no2`;
        ;;


    *) echo "Please Enter Valid Choice";
esac