Converting a Double into a Matrix of its Digits

How can I convert the 3-by-1 matrix A into the 3-by-3 matrix B in the simplest way?

A = [ 123; 456; 789 ];

B = [ 1 2 3; 4 5 6; 7 8 9 ];

Answer 1

[Azzi Abdelmalek]

A = [ 123; 456; 789 ]
B=num2str(A)-'0'