First Few Days of Class-Matrix Modelling

Sept 14th 2009:
The third and forth parts to matrices are "Scalar" multiplication(matrix multiplied by a scalar quantity measure), and "Matrix" multiplication. Matrix multiplication can only be done

when the inner dimensions match

or

the # of rows in the 2nd matrix matches the # of columns in the 1st matrix

*This is where the "Two-Finger Method" is used*

Sept 11th 2009:
On the second day of class we were taught about Matrix Modelling. Every matrix has Rows&Columns(listed in this order) and the numbers in each is an element. The first 2 parts to Matrices are addition and subtraction, which cannot be done unless they have the same number of rows and columns. To do so, thinking of the numbers overlapped will allow you to see the end result.