Calculus Made Easy, 1910: All the little bits

Calculus Made Easy is a book on introductory calculus originally written in 1910 by Silvanus P. Thompson. It was such a well-received text for teaching calculus, that it can still be found in print today (it's now in the public domain and also freely available online).

The first bit of text from the first chapter is fairly intriguing. So much so, that I thought you might like to read it here:

Thinking of the integral of dx as an easy way of saying "the sum of all the little bits of x" is a really intriguing approach to explaining some of the most basic ideas of calculus. 

If you've struggled at all with learning calculus, then you may want to give Calculus Made Easy a read. It may be over 100 years old, but much of the writing is still of great value for the interested student.