A Smarter Math Machine

Casio's ClassPad helps students grasp advanced concepts


After 17 years of arguing that calculators had made many computational skills obsolete, the National Council of Teachers of Mathematics now says it's important that kids master long division and adding fractions. This is a long-overdue development. But I hope that in the reaction against the abuse of technology, teachers don't expel the calculators.

Children today start to use these devices in primary school, and by the time they enter high school math classes the gadgets are indispensable. Used appropriately, advanced calculators can take a lot of the drudgery out of math, and their graphic abilities can help students visualize relationships that are an important part of algebra and calculus.

Often, though, calculator-based activities become exercises in meaningless button-pushing. I have heard far too many tales of high school and even university students who whip out their calculators to do simple addition or who are flummoxed when asked to add fractions--sure signs of inadequate basic math skills.

The Casio ClassPad 300 Plus strikes me as a tool that offers all of the advantages of a graphing machine while also encouraging the development of mathematical understanding rather than calculator technique. Priced at $150, it's just about at the mid-range for graphing calculators from Texas Instruments (TXN ), the overwhelming market leader. But the ClassPad boasts many functions previously available only on computers with special software--and bests many of those offerings in ease of use.

AT FIRST GLANCE, THE CLASSPAD looks like an overgrown version of a cheap pocket calculator, since it lacks the dozens of multifunction buttons that are TI's hallmark. In place of those keys, it features a 16-line, 20-character display, more than twice the size of the screen on the widely used TI-84 Plus. Equally important, the screen is touch-sensitive. This makes it possible to replace the cryptic notations found on calculator keys with much more descriptive on-screen menu items that can be selected with a stylus or, if you're careful, the tip of a finger.

The biggest advantage of the touch screen is that it lets the ClassPad behave more like a computer while retaining the low cost and convenience of a calculator. Like TI's top-of-the-line TI-89, the ClassPad has an algebra system that lets it manipulate both numbers and expressions that include variables. These can be tedious to enter on either device. Unlike TI's model, however, Casio's lets you reuse an expression just by selecting it with the stylus and either copying and pasting it or dragging it to a new location, just as you would in Microsoft Word.

That's a time-saver, but it barely hints at the range of things the ClassPad can do. If you enter an equation and drag it into a geometry area on the screen, the calculator will draw its graph. Even better, if you draw a curve and drag the image to an algebra area, you will get its equation. This allows interesting explorations of the important relationships between algebra and geometry. For geometry, you can use the stylus and drawing tools to create all of the classic compass and straightedge constructions and change shapes simply by dragging points. The one thing that would make the geometry tools better would be a color display. But the higher power demand would require a rechargeable battery, pushing the price toward $200.

For all the ClassPad's virtues, I don't expect to see it turning up in large numbers at schools. After years of cultivating teachers, school boards, and textbook publishers, TI has won more than a 90% market share for its calculators and has an entire curriculum built around some models. Casio hasn't committed the marketing resources needed to make a dent in TI's dominance.

But if you have a child who needs help grasping advanced math concepts, or one who might benefit from some in-depth exploration of mathematical relationships, the ClassPad 300 Plus could be $150 well spent. It's the best sort of educational technology: a tool that can deepen understanding.

For past columns and online-only reviews, go to Technology & You at businessweek.com/go/techmaven/

By Stephen H. Wildstrom

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