foreach (
   0.750
   0.500,
   0.400,
   0.250,
   0.125,
) {
   my $num    = $_;
   my $num_B0 = $num * 4294967296;  # 0..+1 not incl +1.
  #my $num_B1 = $num * 2147483648;  # 0 to just over +1.

   printf("%f = %s B0$/",
      $num,
      unpack('B32', pack('N', $num_B0)),
   );
}

__END__
output
======
0.750000 = 11000000000000000000000000000000 B0
0.500000 = 10000000000000000000000000000000 B0
0.400000 = 01100110011001100110011001100110 B0
0.250000 = 01000000000000000000000000000000 B0
0.125000 = 00100000000000000000000000000000 B0