HP HP-21 - Getting Started; Introduction; Power Onn

Getting Started
Introduction
Congratulations!
Your HP-21 is another professional-quality pocket instrument
from the Hewlett-Packard line of calculators—calculators
whose durability, small size, and ease of operation have made
them the choice for use by climbers on the frigid crags of Mt.
Everest and astronauts orbiting the vast depths of space, as well
as doctors, engineers, scientists, and other people who require
instant, accurate answers to complex and highly technical
problems. You’re in good company with HP!
This handbook has been designed to help you get the most from
your HP-21 and in its pages you’ll find a reference guide to
every basic operation your calculator can perform.
But HP hopes that you’ll use this book as more than a reference.
The secret to getting the most from your HP-21 lies in the
amount of confidence you have in your calculator. And you’ll
build this confidence and learn the calculator’s functions most
quickly by sitting down with your HP-21 and working through
this handbook page by page.
Even if you’ve used other pocket calculators, you’ll want to
take a good, hard look at this handbook. Your HP-21 has
unique features which make complex problem solving easy.
When you see the simple power of the HP system, you’ll be-
come an apostle just as have some half-million HP owners
before you.
So get to know your HP-21. It’s easy!
Power On
Your HP-21 is shipped fully assembled, including a battery.
You can run the calculator on battery power alone or you can
connect the battery charger and use the calculator while the
battery is charging. If you want to use the calculator on battery
power only, charge the battery for 6 hours first. Whether you
operate from batteries or from the charger, the batteries must
be in the calculator.
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