This is really worth reading. It is from his book, “Introduction to Mathematics”, published in 1911.
whitehead intro to math negative nos
A. N. Whitehead on negative numbers (1911)
Filed under abstract, arithmetic, Number systems, teaching, Uncategorized
Saving school math 
The chat about Germany as a ” practical nation” is amusing.
Readers can find the complete book, free for the download, here: http://www.gutenberg.org/ebooks/41568
I am not convinced Internet Archive did due diligence on this one, but “Aims of Education” is also available, free for the download, here: https://archive.org/details/AlfredNorthWhiteheadAimsOfEducation1967
It is unfortunate that Whitehead’s name is so intransigently associated with “The Principia Mathematica.” While he certainly did a great deal of the work in that monumental trilogy, when he was done with it, he was finished. (Russell, in contrast, was devastated by Godel’s results.) Quite aside from being the leading metaphysical thinker of the 20th C., Whitehead was an extraordinary educator, and his writings on pedagogy compare well with those of Dewey.
Anyone interested in learning more about Whitehead, I am told this is a fairly good resource: http://www.iep.utm.edu/whitehed/
It gives a greater understanding(esp. The final few sentences) of a ‘best’ way to teach understanding of add and subtract.
And he has a go at complex numbers as well. I have the book if you want to see more.