This is the first program I made. It's relatively simple but it helped me understand the basics.

use warnings;
use strict;

print "What is your name?";
my $name = <STDIN>;
chomp $name;
print "Hello, $name:)\n";

print "How old are you? ";
my $age = <STDIN>;
chomp $age;
print "You are $age years old!\n";
$age = $age / 2;
print "Half your age is $age years.\n";
my $sum;

    {
    print "Enter a number... ";
    $sum = <STDIN>;
    chomp $sum;
    if (! isNumber ($sum))
        {
        print "Please use numrals.\n";
        redo;
        }
    else    
        {
        last;
        }
    }
    
my $nextsum = $sum / 2;
print "Half of $sum = $nextsum";
sub isNumber
{
my $value = shift;
return $value =~ /^[.\d+-eE]+$/;
};
print "\nTell me $name, would you like to try a test? Yes or No.\n";
    
    {
    my $answer = <STDIN>;
    chomp $answer;
    
    if ("no" eq lc ($answer))
        {
        print "Oh well, have a good day!";
        exit;
        }
    
    if ("yes" ne lc ($answer))
        {
        print "Please answer yes or no $name\n";
        redo;
        }
    }

print "The question is: What is the square root of 36?\n";
my $answertwo = <STDIN>;
chomp $answertwo;
print "Correct! Have a good day!" if "6" eq lc ($answertwo);

print "Sorry, you're wrong. Have a good day!" if "6" ne lc ($answertwo
+);
[download]

As you can see, it goes like this:

What is your name?your name
Hello, your name:)
How old are you? 34
You are 34 years old!
Half your age is 17 years.
Enter a number... 5
Half of 5 = 2.5
Tell me your name, would you like to try a test? Yes or No.
yes
The question is: What is the square root of 36?
seven
Sorry, you're wrong. Have a good day!
[download]