In System Preferences » Keyboard » Shortcuts you need to have enabled Full Keyboard Access. The shortcut to toggle it is (fn-)Control-F7. After that you can tab through all controls and navigate to the Mouse Keys checkbox and check that.
I also recommend Welch Labs’ Neural Network Demystified-series[0]. It is a combination of the Coursera course and the YouTube videos. It get’s into some of the math, while still keeping it basic.
While we’re at it, Knuth has also released a book (which is just transcripts of 5-6 lectures) wherein he discusses the 3:16 project: "Things a Computer Scientist Rarely Talks About"