Here is one way to do it:

my $precision = 8;
for (0..20)
{
  my $var = int(rand($precision));
  print $var/($precision-1), "\n";
}
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Even if the output of rand is not an int, it still is one value among a list of possible ones. Here that fact is explicit rather than implicit, and you get to chose the size of that list.

Maybe Crypt::Random would be a better fit, since you provide a length in bits for the random number, you just have to map 0 to 0, and ~0 to 1 (ie, divide the big unsigned int by the max value).