A Natural Approach to the Number e
Helen M. Doerr, Donna J. Meehan, and AnnMarie H. O’Neil
February 2012, Volume 105, Issue 6, Page 432
Building on prior knowledge of slope, this approach helps students develop the ability to approximate and interpret rates of change and lays a conceptual foundation for calculus.
Calculus and Higher Level Mathematics
Reasoning and Proof