Calculator

It may seem like the pocket calculator is a thing of the past, as your computer, PDA, and perhaps even your mobile phone have built-in calculators. Still, a pocket calculator is a reliable device to have around the house for helping with bills or balancing the checkbook. Portable, lightweight, and usually featuring a large display, a pocket calculator doesn't require you to go through ten submenus to access it.Slightly more sophisticated are graphing calculators. A graphing calculator is a calculator that features much more advanced programming skills and is capable of plotting lines on a graph and displaying the results. These calculators are capable of handling even advanced multi-variable calculus equations. Graphing calculators are actually required in many classrooms at the high school and college level. Most graphing calculators on the market today also feature simple word processing programs, basic computer programming languages, and the ability to communicate with other calculators. In some cases the instructor will require you to get a specific model so that the whole class can learn to program their calculators together--if this model seems out of your price range, you might be able to purchase a used version of this year's or last year's model to save a significant amount of money.The leading manufacturers of graphing calculators have always been HP and Texas Instruments. Today, the TI-89 is the gold standard of graphing calculators, and people in academics and industry appreciate its sleek look and powerful functionality. While HP stopped producing calculators in 2003, its HP 12c calculator is still on the market, virtually unchanged from its introduction over 20 years ago.