How to simplify a number 

Part of being approximate is simplifying numbers.
We trade accuracy for greater convenience.
We substitute a nearby number which is easier to work with, or to remember.
We look for a number which is more convenient, but which is still close enough.
Some ways to simplify a number...
Comments encouraged.  Mitchell N Charity <mcharity@lcs.mit.edu> 
Notes: Doables: Need a discussion of "how close is close enough?". And ways of describing closeness [percent error, etc] Dimensional analysis as an extreme form of rounding. Quantity calculus as "simplifying"? History: 1998.Jul.02 Added History, Doables (mostly from Notes). 1997.Aug.02 last change 1997 created