my $option = 10;
while (1) {
   print"choose 1  or 2 \n";
   my $choice=(<STDIN>) or last;
   if ($choice == 1) {
      &flashcard($option);
   }
   elsif ($choice == 2) {
      print"enter  random range\n";
      my $option = (<STDIN>);
   }
   else {
      last
   }
}

sub flashcard {
   my $option = shift;
   my $random = int(rand($option));
   # do stuff with $random
}