Accessories

The best calcualtor for the beginner and experienced
Because of two differnt keypads, it can be useful for everybody.
A lot of Calculus book has problem solving procedures for TI84 calculator and you can use TI84 keypad to follow the book.
The other keypad would be useful when you get more familier with this calcualtor for more advanced mode usage.

Great for high school
I just got this for my algebra 2 class and it works wonders in there. Problems become easier and more understandable, and if i need help from my teacher I can switch the keyboards and not have to worry about them not knowing how to work the calculator.

Great concept, flawed implementation
Strengths:

The document management system -- multiple "problems" can be kept in the calculator at the same time, and each problem keeps its own variable names; good graphing capabilities; ability to split the screen and work with multiple views of the same problem; spreadsheet application. The calculator has 5 "applications" (calculator, graphs & geometry, spreadsheet, data & statistics, notes), and information can be shared between them.

Weaknesses:
The documentation is very poor. There are two user guides, with considerable overlap in the contents. In User Guide Part 1, which comes packaged with the calculator, there are 25 pages on the Graphs & Geometry application, and the information on how to actually plot a graph is barely mentioned. User Guide Part 2 comes as a PDF file, and has more detail, but is badly organized and missing a lot of information. For example, instructions for a number of operations say to "drag" something, but nowhere in the manual does it say how to do that.

Keypad: other reviewers have commented on the difficulty pressing the right buttons on the keypad. Even worse is the "mouse" operation. I finally discovered that dragging involves holding the center "Click button" while pressing the arrow keys on the "NavPad". It is very difficult to control the cursor with the NavPad, and doubly so when trying to hold down the click button. Also, what operation is done by a click or drag is dependent on where on the screen the cursor is, and it's difficult to control the cursor location with the level of precision needed.

TI-84 compatibility: This seemed like a great idea. However, as far as I can determine, there's no way to integrate TI-84 functions with TI-Nspire functions. When you put in the TI-84 keypad, you get a TI-84. With the TI-Nspire keypad, you get a TI-Nspire. If you want to transfer information from one to the other, it seems to be impossible. The only relevant information in the documentation about TI-84 mode is a warning that if you update the operating system, all your added TI-84 applications will be deleted.

Lack of software: The TI-84 has a lot of user-contributed software. There's almost nothing on the TI web site for the TI-Nspire. I also didn't find much with a web search, and some of what is available requires the CAS version. For example, there don't appear to be any built-in physical constants or conversion factors for units. I could switch to TI-84 mode and get them, but then what's the point of buying the TI-Nspire?

Summary:

This calculator does not appear to be well-engineered or well-supported by TI. I would recommend waiting to see whether they give it the support that it deserves.

A True Leap
I began using Texas Instruments' graphing calculators with the TI-83. In addition, I've used the TI-81 and TI-82. I've seen the calculators improve through the TI-83+, the silver edition, and the TI-84+ and its flavors. They were all improvements and refinements, but not revolutionary. My classroom uses them all and, except for the TI-81 and 82, it's not a problem.

The TI-Nspire is truly a new design. Texas Instruments has implemented a true file system, a great display, "pretty print", and a nice, organized interface for solving problems. Even better, the student can save the problems, link graphical, numerical, and spreadsheet analysis, and even add notes. The ambitious teacher could even create calculator-based problems that utilize all these features and load them on student calculators.

I'm interested to see if I can get a few of these for next year. Then I can talk about how well it works out in a classroom.

There are some distinct drawbacks. The greatest is the keyboard. I like the letters. For quick notes, they're fine. Unfortunately, there isn't quite enough room for my fingers. I keep bumping letter keys. Just a tiny bit extra space would be great! In addition, some functions, such as editing a solution, are not obvious. Nor is moving files around obvious.

This calculator is compatible with the CBL with the TI-84 keyboard installed, but I hope to see this functionality added with its regular keyboard. I also hope that TI soon releases software so that I can use this calculator with my Mac or even my Linux machine.

Overall, I like the machine, but it does need some polish.

Edit (4-29-08): I recently ran into an irritation. While "playing" I decided to have the calculator find a limit of a function. The calculator informed me that I needed to have a CAS. It really bothers me that TI would include features on this calculator that it cannot actually perform.

Great high school maths handheld
This is not a calculator -- it is a handheld computer. Built from the beginning with a different model of use the the traditional graphing calculator, it enourages users to link multiple representations of mathematical concepts. The document model allows teachers to build explorations for students to work with. Students can save their work, and continue on a later date from where they left off. With the included TI-84 Plus faceplate, it is fully backwards compatible with the 84+ family of products.
An excellent choice for high school maths.