There are currently 4 types of TI-NSpire Graphing Calculators:
The original TI-Nspire CX and TI-Nspire CX CAS(2011) calculators.
The most recent TI-Nspire CX II and TI-Nspire CX CAS II calculators were released in 2019.
TI-Nspire CX II CAS Calculator
Of the 4 TI-Nspire CX Calculators the TI-Nspire CX II CAS Calculator is the best: It is newer than the other two CX
(which means more memory [64MB], significant faster processing speed (396 MHz vs 132MHz), better battery duration. Not to mention
new built-in functionality such as Laplace and Fourier Transforms, Python scripting (in addition to LUA and TiBasic) and more.
The TI-Nspire CX II CAS Calculator additionally has the built-in Computer Algebra System (CAS) which the TI-Nspire CX II Calculator does not have.
Yet, both calculators costs the same price. So if you are in the market for a new TI-Nspire CX Calculator make sure you see the CAS symbol on the top right.
Also, make sure your school permits the TI-Nspire CX II CAS Calculator, some schools only permit the non CAS TI-Nspire CX II Calculator.
The best selection and best prices for Texas Instruments TI Nspire can be found at Amazon.com and Walmart.
At Amazon you have the option of either buying a new TI-Nspire CX II Calculator or to buy a used/renewed one.
The short answer is: It depends! Read the advantages for each calculator below.
5 Reasons in favor of the TI-Nspire CX II:
1) The TI-Nspire CX II has a Computer Algebra System (CAS) which is what you need in Calculus, PreCalculus, Algebra, Engineering classes to solve Equations, find Derivatives and Integrals, etc.
The TI-84 does not have CAS and cannot help in that regard.
2) Stylish blue/black design, computer connectivity using the free TI-Nspire Student Software.
3) The TI-Nspire CX II can be used through College. Their OS is being updated regularly.
4) Many preloaded Math, Finance and Science Apps. Free Games can be downloaded at https://www.ticalc.org/pub/nspire/lua/games/ .
5) The TI-Nspire allows for STEP BY STEP Apps for Algebra, Calculus, Physics, Chemistry, etc to be downloaded at www.TinspireApps.com
5 Reasons in favor of the TI-84 Plus CE:
1) The TI-84 is just easy to use. Everybody loves the simplicity and user friendliness.
2) Colorful screen and design. Cannot beat that! Computer connectivity using the free TI-Connect CE Software.
3) Use your TI-84 Plus CE to Code in Python on the Go. Nothing beats that.
4) The TI-84 has a greater memory which allows for many APPS, GAMES and more.
5) Charge your TI 84 like a cell phone. No need to replace batteries anymore.
You may downlad the free TI-Nspire CX II Titanium Manual (PDF) here:
TI-Nspire CX II Calculator Manual
SAT: yes, all 4 TI-Nspires are premitted: CX, CX CAS , CX II, CX CAS II
ACT: yes, only the 2 non-CAS TI-Nspires are permitted: CX and CX II.
Read: ACT approved Calculators