Here is an enhancement: you can use a hash to show all guesses and to notify the user that a guess was already used. I also fixed your range check to match your printed advice (1 to 100). Finally, I used perltidy. 
use Modern::Perl;

my $target = ( int rand 100 ) + 1;
my $number = 99;

my %guesses;
GUESS: foreach my $guess_num ( 1 .. $number ) {
    say "($guess_num) Please enter a guess:";
    my $guess = <>;
    chomp $guess;

    if ( ($guess =~ /\D/) or ($guess > 100) or ($guess == 0) ) {
        say "This guess is out of range. Guess between 1 and 100!";
        redo GUESS;
    }

    if ( $guess == $target ) {
        say "Congrats, you guessed right!";
        last GUESS;
    }

    elsif ( exists $guesses{$guess} ) {
        say "You already guessed $guess.";
    }

    elsif ( $guess < $target ) {
        say "Your guess of $guess was too small.";
    }

    elsif ( $guess > $target ) {
        say "Your guess of $guess was too big.";
    }

    $guesses{$guess}++;

    print "your previous guesses: ", join ' ', sort {$a <=> $b} keys %
+guesses;
    print "\n";

    if ( $guess_num == $number ) {
        say "You have used all your guesses. Please try again.";
        last GUESS;
    }
}

[download]

In reply to Re: Number guessing game by toolic
in thread Number guessing game by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.