Hints for Solving Quantitative Problems                                                                                           Dr. Laura Sanders

 Solving quantitative problems is a crucial aspect of scientific and engineering work.  Your colleagues, supervisors, and clients will make decisions based on your calculations.  There may be a whole lot riding on your work, including your clients' or the taxpayers' money, people's health and safety, and/or our understanding of Earth processes.  As a result, it is important to base your calculations on a logical progression of steps, present them neatly and carefully, and explain them in words and terms your reader can understand.  Below are some guidelines for approaching the task.
 START THIS WAY: w Start with lots of clean scratch paper. w Write information given, and write what you need to find. w Sketch a diagram illustrating the situation. w Decide whether you need additional information, and if you do, find it. w Determine if you can use established formulas, and if so, make sure they are applicable to your situation. w Break the process into several smaller parts.  Solve each part in a logical sequence of steps that take you from what you know to what you want to know.  w Use dimensional analysis (see this helpful link!).  It will help guide your solution. w At each step, write a brief explanation--in words!--of what you are doing.
 WHEN YOU HAVE AN ANSWER: w Check to be sure your answer is reasonable.  If possible, try to imagine how big, how much, or how long the final quantity is in real, physical terms.  Does it make sense?  If appropriate, try comparing your answer to published typical values for the quantity in question.  w Check to see that you included units of measurement, and that the answer is in a convenient unit of measurement and a meaningful order of magnitude. w Check the number of significant figures (significant digits) in the answer.   See these resources for a review:                      http://www.chem.tamu.edu/class/fyp/mathrev/mr-sigfg.html       OR         http://www.usca.edu/chemistry/genchem/sigfig.htm and http://www.usca.edu/chemistry/genchem/sigfig2.htm