# Matrix Notation

Matrices are rectangular arrangements of elements. The dimension of a matrix is given with *m* × *n* where *m* is the number of rows and *n *is the number of columns. The elements are identified with subscripts giving the row, *j*, and column,* k*, shown as *a _{jk}* for the elements of a matrix A.

When multiplying the matrices, the number of rows in the first matrix has to equal the number of columns in the second. Given matrices A and B where A has dimension 2 × 3 and B has the dimension3 × 2, the resulting matrices are found as follows: