use Text::CSV;
use Math::MatrixReal;

my $mref = [
  [ '5', '4', '4', '2', '4' ],
  [ '9', '6', '4', '4', '3' ],
  [ '2','73','96', '6', '8' ],
  [ '2', '4', '9','87', '8' ],
  [ '2', '4','10', '6', '8' ],
];

my $matrix = Math::MatrixReal->new_from_rows( $mref );

# At this point $matrix is a Math::MatrixReal object that
# resembles the one you showed us a Data::Dumper dump of.

my $csv = Text::CSV->new;
open my $FILE, ">", "./whatever.csv";

foreach my $row_num ( 1 .. 5 ) {
  $csv->print(*STDOUT, [ map { $matrix->element($row_num,$_) } 1 .. 5 ] );
  print {*STDOUT} "\n";
  $csv->print($FILE, [ map { $matrix->element($row_num,$_) } 1 .. 5 ] );
  print $FILE "\n";
}