This is paper no. 16 in the list on p. . This paper, which originally appeared as the cover article for the American Mathematical Monthly in March 1992, has recently been reprinted in a special volume (Canadian Math Society Proceedings, vol. 20 ) which is the proceedings of the Organic Mathematics Workshop (see section 5.1). I am somewhat diffident about putting this paper in a list of my `best' because I was also an editor of that proceedings; nonetheless the paper was chosen out of several possibilities not by me but by my co-editors Jon and Peter Borwein (who are Chauvenet prize-winners.)
The content of the paper has served as the basis for my understanding of the interaction of numerical methods and chaotic dynamical systems, and has stood up remarkably well in the face of rapid progress in the area.