Section 1: Getting Started29
 Keystrokes Display × 66.0000 The final answer.
Notice that you didn’t have to write down or remember the intermediate answers before you multiplied. The HP-41C automatically stacked up the intermediate results for you and brought them out on a last-in, first-out basis when it was time to multiply.
No matter how complicated a problem may look, it can always be reduced to a series of one- and two-number operations.
Now try these problems. Remember to work through them as you would with pencil and paper, but don’t worry about intermediate answers—they are handled automatically by the HP-41C.
 (16 × 38) – (13 × 11) = 465 (27 + 63) ÷ (33 × 9) = 0.303 (√(16.38 × 5)) ÷ .05 = 180.997 4 × (17 – 12) ÷ (10 – 5) = 4
###### Before You Continue...
Now that you’ve learned how to use the basic features of the calculator, you can begin to fully appreciate the benefits of the Hewlett-Packard logic system. With this system, you enter number using the parenthesis-free, unambiguous method called RPN.
It is the RPN system that gives you all of these advantages while you are using the HP-41C:
• You work with only one function at a time. The HP-41C cuts problems down to size instead of making theme more complex.
• Functions are executed immediately. You work naturally through complicated problems, with fewer keystrokes and less time spent.
• Intermediate results appear as they are calculated. There are no ‘‘hidden’’ calculations, and you can check each step as you go.
• Intermediate results are automatically handled. You don’t have to write down long intermediate answers when you work a problem.
• You can calculate in the same manner you do with pencil and paper. You don’t have to think the problem through ahead of time.
• There is no need to worry about parentheses in the calculation; RPN eliminates the necessity for entering parentheses.
The Hewlett-Packard RPN system takes just a few minutes to learn. But you’ll be amply rewarded by the ease with which you and your calculator will glide through the longest, most complex equations. With the HP-41C, the investment of a few moments of learning yields a lifetime of mathematical dividends. Work carefully through this handbook so you can get the greatest value from your new HP-41C.