Conversions / Constants:

Most conversions involve only one scaling factor (e.g. currency conversions or length conversions). Storing an often-used conversion factor in a memory location can make conversions easy.

For example, to convert millimeters and inches the conversion factor is 25.4 millimeters per inch. By storing 25.4 in memory location 6, conversions can be done easily.

e.g. 5 inches to millimeters:  5 [f] [RCL] [6] [x]

Minimizing Keystrokes:

RPN beginners often overuse the [Enter] key. It is needed to separate the entry of two or more keyed-in numbers; otherwise, it should be used sparingly. If the second number is coming from a memory location or [last x] or [last y], [Enter] is not necessary after the first number. The stack will lift automatically.

Judicious use of the stack, memories, and [last x] and [last y] can save keystrokes. With a visible stack, Access RPN and Active RPN make it easy to keep track of results for greater efficiency.

RPN provides a challenge to find the most logical approach to a problem, and rewards those efforts with a concise and powerful execution for results.

Programming:

Editing:

While programming, the back arrow key can be used to delete current program step. This is the only editing available while keystroke programming. Version 1.1 introduced the “CODE” button which allows subsequent editing and copying/pasting of code.

To Erase a Program (e.g. Program Key “B”):

[f] [Prog] [B]

Touch the 3 text fields...  [next]

[REC] [Done]

Long Programs, Intermediate Results or Intermediate Input:

Try using 2 or more programs in succession to meet these requirements.

Tips to Shorten Programs:

Make full use of the stack.

Use  [x exchange y], [last x] and [last y] to full advantage.

Put large constants into memories instead of typing them.

Rounding Effects and Decimal Places:

Access RPN and Active RPN store most numbers internally with 10 significant digits. If the result of a calculation is actually 4.999999627, it appears as “5” because the calculator displays up to 6 decimal places. If the “5” is multiplied by 100, instead of getting “500” as one may expect, “499.999963” will appear. This is not an error, but simply the result of carrying 10 significant digits internally.

e.g.                     x 1000 = 3141.592654

The display of decimal places is handled automatically, normally displaying between 0 and 6 places as necessary. This depends on the precision of the answer and on the number of places to the left of the decimal. The scientific notation mode is an option when working with very large or very small numbers, and always displays 6 places.

As with most calculators and computers, often the displayed result implies an accuracy not warranted by the inputs. For example, if the inputs for a division both have 3 significant digits, the significance of the result will also be restricted to 3 digits, despite the fact that the calculator may display many more.

Visualization:

Always check that results appear reasonable. These apps help by providing last operation details, often including a simple bar graph that helps visualize results.