use strict;

{
	package Calculator;
	use List::Util qw/reduce/;
	sub add      { reduce { $a + $b } @_ }
	sub multiply { reduce { $a * $b } @_ }
}

{
	package main;
	use Test::More tests => 2;
	
	# Calculate the fifth triangular number
	is(
		Calculator->add(1 .. 5),
		15,
		);
	
	# Calculate five factorial
	is(
		Calculator->multiply(1 .. 5),
		120,
		);
}