my $num1 = 0.29;
my $num2 = 50;
my $num3 = $num1 * $num2;
print "num3=$num3\n"; # is '14.5'
##</code><code>##

my $num4 = sprintf ("%.64f", $num7);
##</code><code>##

my $num1 = 0.29;
my $num2 = sprintf ("%.64f", $num1);
my $num3 = 50;
my $num4 = sprintf ("%.64f", $num3);
my $num5 = $num2 * $num4;
my $num6 = sprintf ("%.64f", $num5);
my $num7 = $num1 * $num3;
my $num8 = sprintf ("%.64f", $num7);
my $num9 = eval(eval($num1) * eval($num3));
my $num10 = sprintf ("%.64f", $num9);

results in

num1=0.29
num2=0.2899999999999999800159855567471822723746299743652343750000...
num3=50
num4=50.000000000000000000000000000000000000000000000000000000000...
num5=14.5
num6=14.499999999999998223643160599749535322189331054687500000000...
num7=14.5
num8=14.499999999999998223643160599749535322189331054687500000000...
num9=14.5
num10=14.50000000000000000000000000000000000000000000000000000000...