Maybe it was "Calculus Made Easy", by Silvanus P. Thompson? That's an old book that explains the basic idea of integration and differentiation, but doesn't try

Maybe it was "Calculus Made Easy", by Silvanus P. Thompson? That's an old book that explains the basic idea of integration and differentiation, but doesn't try to be rigorous at all. http://www.scribd.com/doc/8533492/Calculus-Made-Easy-by-Silvanus-P-Thompson http://www.scribd.com/doc/8533492/Calculus-Made-Easy-by-Silv...