count=0
while [ $count -eq 0 ]
do
    tput clear
    echo "1. Addition"
    echo "2. Subt"
    echo "3. Multi"
    echo "4. Divi"
    echo "5. Exit"
    echo -e "Enter Yr choice : \c"
    read choice

    if [ $choice -ne 5 ]
    then
        echo -e "Enter first number : \c"
        read a
        echo -e "Enter second number : \c"
        read b
    fi
    case $choice in
    1)    ans=`echo $a + $b | bc`
        echo "Addition is $ans"
        ;;
    2)    ans=`echo $a - $b | bc`
        echo "Sub is $ans"
        ;;
    3)    ans=`echo $a \* $b | bc`
        echo "Multi is $ans"
        ;;
    4)    echo scale=2 | bc
        ans=`echo $a / $b | bc`
        echo "Divi is $ans"
        ;;
    5)    exit 1
        ;;
    *)    echo "Invalid Choice !!!"
        ;;
    esac
    sleep 3
done