Mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes, and the spaces in which they are contained. More importantly a general understanding of math and a decent skill of crafting formulas is almost a most if you want to get into many topics in computing.
Here are some of the notes I have on some areas of Math:
Here are also some notes I have on some math concepts:
Finally here are some notes I have on Mathematicians:
Many of these are still a work in progress