use Math::BigFloat;

$moritzFactor = Math::BigFloat->new( 1 )->bsub(
    Math::BigFloat->new( 1 )->bdiv(
        Math::BigFloat->new( 2 )->bpow( 128 )
    )
);

print $moritzFactor;
;;
1

[0] Perl> print $moritzFactor->bstr;;
1

[0] Perl> print $moritzFactor->bsstr;;
1e+0