Shell Programming and Scripting

echo "Enter 1 to Add"
echo "Enter 2 to Subtract"
echo "Enter 3 to Multiply"
echo "Enter 4 to Divide"
echo "or q to quit"
while [ "$Enter" != "q" ]
do
read Enter
case $Enter in
1) echo "Add"
echo "Enter a number"
read num1
echo "Enter another number"
read num2
sum=$((num1 + num2))
echo "The sum of number 1 and number 2 is: $sum";;
2) echo "Subtract"
echo "Enter a number"
read num1
echo "Enter another number"
read num2
sub=$((num1 - num2))
echo "The difference of number 1 and number 2 is: $sub";;
3) echo "Multiply"
echo "Enter a number"
read num1
echo "Enter another number"
read num2
prod=$((num1 * num2))
echo "The product of number 1 and number 2 is: $prod";;
4) echo "Divide"
echo "Enter a number"
read num1
echo "Enter another number"
read num2
div=$((num1 / num2))
echo "The quotient of number 1 and number 2 is: $div";;
esac
echo "Enter another selection or q to quit"
done

q) exit;;