HP HP-28S User Manual

4
Repeating Calculations
In this chapter you'll create an expression containing numerical vari-
ables
and then use a calculator feature called the Solver to evaluate
the expression for various values of the numerical variables.
In
chapter 2 you made a calculation by keying in an expression that
contained numbers and then evaluating the expression. In this chapter
you'll create an expression by calculating on the stack, using names as
symbolic
arguments. You'll use the Solver to assign values to the vari-
ables and evaluate the expression. Each time you evaluate the
expression, the calculation is made with the current values of the vari-
ables.
If you change the value of one or more variables, you can
simply evaluate the expression again to recalculate with the new
values.
In
chapter 3 you created numerical variables and a program variable.
In this
chapter you'll create expression variables and name variables.
(Remember,
any object can be stored in a variable.) You'll also learn
about directories, which are sets of variables.
Creating an Expression
We'll repeat the resistance calculation from "Chain Calculations" in
chapter 2, only this time we'll use names, rather than numbers, as
arguments. Recall
that the formula for the circuit is:
1
1
+
1
58 4: Repeating Calculations

HP HP-28S Specifications

General

Introduced	1988
Memory	32 KB
Number of Digits	12
Type	Scientific Calculator
Manufacturer	Hewlett-Packard (HP)
Display	LCD
Processor	Saturn
Programming	RPL

Summary

HP-28S Advanced Scientific Calculator Owner's Manual

Part 1: Fundamentals

Introduces basic operations, calculator features, and core concepts.

Getting Started

Covers initial setup, basic operations, and calculator overview.

Doing Arithmetic

Explains methods for performing calculations using stack and expressions.

Part 2: Summary of Calculator Features

Objects

Describes fundamental data types, symbolic operations, and programming elements.

The Command Line

Explains input methods, cursor control, and command entry.

The Stack

Reviews stack concepts and commands for manipulating objects.

Part 3: Programming

Program Structures

Covers conditional logic, loops, and error handling in programs.

Conditional Structures

Explains testing conditions and making decisions within programs.

Definite Loop Structures

Details structures for executing code a specific number of times.

Appendixes & Indexes

Appendix A: Assistance, Batteries, and Service

Provides troubleshooting, battery info, and service details.

Answers to Common Questions

Addresses frequent user queries and common calculator issues.

Appendix B: Notes for HP RPN Calculator Users

Highlights differences for users familiar with RPN calculators.

Appendix D: Menu Map

Lists commands by menu, with descriptions and page references.

Contacting Hewlett-Packard