use strict;
use warnings;
use Math::BigInt;

my $x = Math::BigInt->new(17);
my $y = 70 / $x;

print $y, "\n";

$x = "$x.00";
#or:
#$x = "$x";

$y = 70 / $x;

print $y, "\n";

__END__

Outputs:
4
4.11764705882353