New models of graphing calculators arrive on a regular basis. Texas Instruments alone introduced 8 models in a 10 year period. At many schools it is impractical or impossible to have every student use the same model and often different brands as well as different models are used in the same classroom. This situation brings about both advantages and disadvantages for a college algebra instructor. Calculators differ in how they handle the order of operation and in the number of pixels in the graphical display. When instructors are aware of these differences, they can use the calculators to provide instruction on concepts such as appropriate use of parentheses, aspect ratios, and vertical asymptotes. Specific examples are given. Scatterplots and regression analysis are now common in college algebra textbooks. Producing these on a calculator is a relatively complicated procedure compared to the usual types of calculations students are expected to do. Teaching this to students can be handled by using a general procedure given at a level that works on any model accompanied by more specific details on a case-by-case basis. Breaking the details into pieces makes the regression analysis easier for the students to grasp. (Contains several figures of calculator activity.) (DDR)