01. Matrices, accessible version 19.05
02. Matrices: examples, accessible version 21.16
03. Bigger matrices, accessible version 24.01
04. Matrix multiplication, 1, accessible version 11.14
05. Matrix multiplication, 2, accessible version 9.14
06. Matrix multiplication, 3, accessible version 11.43
07. Index notation, accessible version 10.09
08. Other operations, accessible version 12.49 (anything beyond 5.20 is optional)