A calculator can be a useful tool to save time and check arithmetic, but also to do calculations and explorations which would not be manageable otherwise.  However, you should not become overly dependent on your calculator.  There are basic skills in calculus which we believe you should be able to carry out "by hand."   A graphing calculator can be useful for your personal use in study and on homework assignments.  A few homework problems in the text have a "calculator icon" beside them and usually require a graphing calculator. Some fancier graphing calculators also contain a "Computer Algebra SYstem" (CAS) that can do not just numeric work but also algebraic mainpulations and some of the procedures we study in calculus.  If you have one of these, it can be useful in chekcing your work, but you should not use the capability so much that it lets you ability to do manipulations by hand "go to seed." If you are looking for a new graphing calculator, we find that the TI-83 and TI-84 series are especially useful for math majors.  These series contain certain built-in statistical distributions that are needed in Math 320 and very handy to have whenever anyone is working with probability and statistics.  Some calculators which are fancier in other ways do not have these distribtuions (although they may be downloadable from the web). If you have a TI-83 or a similar TI calculator, the link Information for TI-83 Use in Calculus I, II  might be helpful.       For all exams and quizzes in the Math 131, however, no graphing calculators will be allowed.  A simple scientific calculator (arithmetic, ability to       evaluate trig, exponential and logarithm functions) will be permitted, however.  If you don't have access to one, you can probably buy one that is       adequate for about $10.   Use of a graphing calculator at an exam or quiz is an academic integrity violation.