sub getArray {
    my $n = $_[0];
	my @examples = (
	    "The population of the U.S. is ${\($n*340389145)} people",
	    "The frequency is ${\($n*13824)}Hz",
	    "This is a real number, ${\($n*723540.34034)}",
	    "${\($n*1045.357)}",
	    "${\($n*834569.334656)}",
	    "${\($n*1000000)} B.C.",
	    "My daily compensation is \$${\($n*2234.36)} per hour.",
	    "${\($n*2349134)}",
	    "${\($n*123456)}",
	);
    return @examples;
}

my $n = 4;
my @have = getArray(1);
my @want = getArray($n);

for my $i (0 .. $#have) {
    my $have = $have[$i];
#   say "$have";
    my $want = $want[$i];
#   say "$want";
    (my $work1 = (($have) =~ s{ \d+\.?\d* }{ $& * $n }erx )) =~ s{ \d+ }{
       $& =~ s/ (?<=\d) (?= (?:\d{3} )+ (?!\d) ) /,/xrg; }ex;

    (my $work2 = $want) =~ s{ (?<int> (\d+)) }{
        $+{int} =~ s/ (?<=\d) (?= (?:\d{3} )+ (?!\d) ) /,/xrg; }ex;

    is $work1, $work2, 'Factor and insert commas where appropriate';
}