loop

stayin="y"
while [ "$stayin" == "y" ]; do
        echo -n "input 1st operand: "
        read an1
        echo -n "input the operator: "
        read op1
        echo -n "input 2nd operand: "
        read an2
        echo -n  "you input $an1 $op1  $an2 =  "
        if [ "$op1" == "+" ]; then
                echo "addition"
        fi
echo "continue (y/n): "
read stayin
done