% MATLAB script demonstrating blockwise matrix multiplication
A = rand(5,5); B = rand(5,5); % Initialize random matrices
C = A*B; % Standard matrix product in MATLAB
% \emph{Blockwise} matrix operations
Aoo = A(1:3,1:3); Aor = A(1:3,4:5); Aul = A(4:5,1:3); Auu = A(4:5,4:5);
Boo = B(1:3,1:3); Bor = B(1:3,4:5); Bul = B(4:5,1:3); Buu = B(4:5,4:5);
C2 = [Aoo*Boo+Aor*Bul,Aoo*Bor+Aor*Buu;...
     Aul*Boo+Auu*Bul,Aul*Bor+Auu*Buu]; 
norm(C-C2),    