Texas Instruments TI-30X IIS 2-Line Scientific Calculator

The device uses solar power when possible but can fall back on the internal batteries (which are included) if there isn't enough light. The buttons wiggle around a little too much and require a firm keystroke to register input, but the fact that input can be followed by looking at the output on the first line helps to cut down on mistakes. There is a shift key that doubles the functions of most buttons, and although the TI-30X IIS isn't festooned with as many buttons or functions as some other calculators we've tested in this price range, it's still very capable. There are three angle modes (degrees, radians, and grads), scientific and engineering notation modes, and even one- or two-variable statistical modes. Five variables can also be assigned to their own memory slots. The documentation is lacking, as everything is presented on a single folded sheet of paper, but Texas Instruments did manage to pack several illustrated examples on the page. The calculator comes with a snap-on cover that fits on the back of the device when you are using it. The calculator carries a one-year limited warranty. --T. Byrl Baker

Pros:

• Two-line display
• Relatively inexpensive
• Handles one- and two-variable statistical calculations

Cons:

• Weak documentation
• Buttons wiggle a bit too much