The two-line display affords a freedom that single-line screens simply can't offer, like the ability to use the EL-531VB's arrow keys to move to any point of the equation you've entered and edit it before calculating the final results. This feature was found only in the most expensive calculators just a few years ago, and it really makes this device easy to use for people of all ages. Another nice touch is the Direct Algebraic Logic entry method, which lets users enter equations exactly as they are printed on a blackboard or in a textbook. Output is purely digital--the calculator can't solve abstract algebra problems and display the results in terms of x and y (or in any other alphanumeric terms)--and the calculator can't produce graphs, but it's excellent for number-crunching and checking work for students who understand the fundamentals of problems they are working on.

Thanks to the use of a shift key, the calculator has 183 functions, including the ability to perform statistical calculations. It also has an extremely clever integrated case cover that slides up and folds flush with the back of the unit without ever being removed from the calculator (meaning it can never be lost). The high-contrast design makes the buttons' notations easy to read, including the shift functions that are listed above each key. --T. Byrl Baker