HP HP48G Plus Graphic Calculator

We had to throw out all of our typical calculator knowledge to use the 48G+, as it uses Reverse Polish Notation (RPN, also known as postfix notation). For example, instead of pressing 2 + 2 = to get an answer, you have to press 2 ENTER 2 +. Once we learned the basics, RPN made complex calculations much easier to enter, eliminating the need for parentheses in most calculations. Studded with buttons and crammed with labels, the keypad looks impossibly crowded, but the color-coded secondary and tertiary function labels are easy to find and decipher with a little practice. A row of buttons at the top is used to select menu items that are displayed onscreen, providing even more functions in a relatively small space. Ultimately, the 48G+ offers more than 2,300 functions, over 300 of them built-in formulas and scientific constants encompassing the spectrum of the mathematical and scientific fields.

Using the 48G+ for a few weeks made it clear why this series of calculators is so popular; they're easy to work with once the initial learning curve is overcome. A complete set of built-in formulas coupled with the calculator's programmability give the device potential limited only by its 128 KB of built-in memory. If you need lots of RAM, its upgradable memory makes the higher-end 48GX a better bet; however, the 48G+ has plenty of storage for all but the most demanding students and professionals. It also comes with an infrared port for communicating with other calculators or a printer, and a connectivity kit--available separately--allows you to link the calculator to your PC for downloading new formulas and other data. --T. Byrl Baker

Pros:

• RPN can speed data entry with practice
• Programmable--you can add nearly any feature you like
• Infrared port lets you communicate with other IR-equipped calculators

Cons:

• Cluttered keypad
• Learning RPN and basic object-oriented programming can be daunting for the novice