Buying Guide for Hand Held Calculators

As the new school year approaches, many people are preparing to buy calculators for their children. The market offers numerous models with varying features. Here is a guide to help you understand the basics.

Graphing Calculators
Typically, most high school students in standard high school level math classes will need a Graphing Calculator. The real issue is deciding which features to choose. All calculators have two types of storage; Random Access Memory (RAM) and Read-Only Memory (ROM). ROM is permanent memory that stays when the calculator is turned off. The machine's operating system lives in ROM, but its calculation data lives in RAM. The difference between these types of memory is whether information is lost when the calculator is turned off. For example, if 2 + 2 were entered the calculation would happen in RAM, but the program that performs the calculation is stored in ROM. Once the calculator is running, it will need a lot of memory to temporarily store data for computations (RAM). Typically, graphical calculators need to have between 32 KB and 256 KB of RAM to perform well. Of course, the more RAM your calculator has, the more information can be processed simultaneously and higher end models will usually have more RAM.

Standard ROM memory is static and cannot be changed. However, most better calculators now offer Flash ROM memory, which is reprogrammable. This technology enables the calculator to be upgraded with new software and operating systems through the internet post purchase much like the hard drive of a computer. Flash ROM memory also allows students to toggle between multiple software applications like a computer that can toggle between Microsoft Word and Excel. This is convenient for students who have multiple math classes. Here is a list of high quality graphing calculators with Flash ROM memory; TI-83 Plus, TI-83 Plus Silver Edition, TI-89 and the Voyager 200.

Computer Algebra System (CAS)
Some calculators have built-in computer algebra systems or CAS. They enable the user to evaluate mathematical expressions symbolically or numerically. These systems can calculate using terms and formulae, solve equations, assist with trigonometry, analytical geometry, vector and matrix calculations as well as calculations of derivatives, limit values and integrals. Needless to say, these are extremely powerful machines. However, they tend to be expensive and may have more power than the student will ever need. Additionally, some high schools have not authorized the use of them. These calculators may be more suited to college level math majors. However, if the user anticipates majoring in math after high school and the school approves of their use, a parent may want to go ahead and buy the CAS calculator, which could continue to be used later. The TI-89 and Voyage 200 have CAS. The TI-82, TI-83 Plus and the TI-83 Plus Silver Edition do not.

Price is another consideration. The TI-82, without Flash or CAS retails at $182. However, the TI-83 Plus Silver Edition has Flash at just $150. The TI-83 Plus also has Flash, but is less of a deal at $182. Calculators with Flash and CAS tend to have high end pricing. The TI-89 is $330 and the Voyage 200 is $335. These prices will fluctuate a little between retailers. Of course, there are always used machines, but I highly recommend securing a lengthy warranty. Because mathematics builds on itself, some of the functions may not even be used until a year or more after the purchase.