Students taking a pre-college or prep mathematics course can use a basic calculator without a graphing function, the Ohio State University Mathematics Department recommends. This includes simple scientific calculators and ultra-portable folding digital calculators such as the Aurora HC127.
You may be able to get by using a calculator program on your computer. The basic calculator included with your operating system will do in a pinch, or you can use a program with additional features, such as Moffsoft's Freecalc for Windows-based systems. Calculator.org has a robust Java-based calculator with scientific functions. Keep in mind that most professors will not allow you to use your laptop during an exam or quiz.
For a basic mathematics course that involves algebraic equations or statistical calculations, a simple scientific calculator is recommended. Several inexpensive models are available, including the popular Texas Instruments TI-30X IIS and the cheaper Casio FX-115ES. Both have the algebraic, fractional and conversion functions that are needed in a college-level basic math course.
Those who are taking a basic course but planning on studying higher-level math may consider investing in a graphing calculator. Graphic calculators are required for college algebra, calculus and physics courses. Texas Instruments has several models available, some of which have useful features like USB connectivity to easily download programs from your computer.
Check your course listings for any specific requirements. Professors often recommend calculators in the course descriptions. Also, drop by your campus bookstore when making your calculator purchase. These bookstores often have several models for sale with a substantial student discount.