Instruct: Classify Amazon reviews into positive or negative sentiment
Query: This is not an RPN calculator

Reverse Polish Notation (RPN) calulators use an <enter> key and do not have an <=>. Look closely at the image for this product: This calculator has an <enter> key and does not have a <=> key, but it's not RPN. The owners manual is useless (written in Spanish). I was so excited to get an affordable RPN calculator and I deflated like the Hindenburg when I figured out I got rooked.I guess I'm just bitter that I spilled coffee on my HP32 and I can't get a replacement for less than $75. Lucky for me there is an RPN calculator app for my Droid. Are you listening HP? Captive generations of RPN-users yearn for a basic $30 RPN calculator.Very Truly Yours.