M N =P if and only if the number of columns of matrix M is the same as the number of rows of matrix N and
pij = mi1n1j + mi2 n2j+ mi3 n3j + ... + mik nkj.
The matrix P has the same number of rows as M and the same number of columns as N.
If a multiplication cannot be performed because of the order of given matrices, the matrices are said to be not conformable. Other Dimensions of Matrices