If you tried to calculate the average from the first task for several input numbers, you might noticed there's no need to sum any numbers. So, I'd implement it as

#! /usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

print 'Please enter a number: ';
chomp( my $limit = <> );
say int(($limit + 1) / 2);
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The C-style for loops are randomly used in Perl. Simple while can be used to solve the second task, I tried to show a solution without an array. A little trickery was needed to separate the numbers by spaces.

#! /usr/bin/perl
use warnings;
use strict;

print 'Please enter a number: ';
chomp( my $limit = <> );
my $n = $limit + 10;
print ' ' x ($n != $limit), $n while ($n -= 10) >= 0;
print "\n";
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To filter an array, we usually use grep in Perl. Also, I tried to really ask for 4 input values, not 3, not 12.

#! /usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

say "Please enter 4 numbers:";
my @numbers;
push @numbers, scalar <> for 1 .. 4;
chomp(@numbers);
say join '-', grep $_ > 50, @numbers;
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For the last task, the repetition operator can hide one level of looping:

#! /usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

my $size = shift;
say '*' x $_ for 1 .. $size;
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