There is no need to use hashes at all. Just shuffle your list of available numbers then move them in chunks of 10 (or whatever) to a list of lists using splice. Then just pop one off when you need it.

#! perl -sw
use strict;
# get available numbers from somewhere.
my @available = (100..999);

# shuffle them
$a = $_ + rand @available - $_ and @available[$_, $a] = @available[$a,
+ $_] for (0..$#available);
my @lists;

# move the randomly distributed numbers into 10 lists 10 at a time.
$lists[$_] = [ splice( @available, 0, 10) ] for 1..10;

# to use and discard the next number from the 5th list
my $next = pop @{$lists[5]};

print "list[$_]=( @{$lists[$_]} )\n" for 1..10;

__END__
# Output Note: The number used and discarded from the 5th list.
C:\test>198405.pl
C:\test>198405.pl
list[1]=( 473 849 328 853 535 166 196 138 466 553 )
list[2]=( 998 533 640 693 564 555 498 766 614 294 )
list[3]=( 527 195 722 886 751 458 134 186 246 556 )
list[4]=( 461 120 694 440 387 221 938 862 971 439 )
list[5]=( 457 957 446 976 397 403 425 748 966 )
list[6]=( 870 877 139 776 496 271 378 811 565 472 )
list[7]=( 942 414 463 358 146 958 168 728 158 338 )
list[8]=( 162 169 509 268 815 716 410 629 965 705 )
list[9]=( 842 468 203 412 651 130 343 539 219 177 )
list[10]=( 734 224 275 658 127 810 874 649 844 633 )

C:\test>
[download]