After numerous supersearches, I still couldn't come up with an answer to my question. I'm in precalc, so to make life easy I wrote up a quick little quadratic equation solver. My question lies not in that however, but rather in why I'm having issues with numeric and nonnumeric strings. my code is quite simple, 
print "A?="; chomp(my $a=<STDIN>);
print "B?="; chomp(my $b=<STDIN>); #get Ax**2+Bx+C values
print "C?="; chomp(my $c=<STDIN>);

my $ans1=(($b x -1)+sqrt(($b**2) - 4 x $a x $c)) / (2 x $a) or die "Un
+real answer!\n"; #note the ugliness of ($b x -1), any better way to g
+et -$b? 
my $ans2=(($b x -1)-sqrt(($b**2) - 4 x $a x $c)) / (2 x $a);

print "Answers:  $ans1 AND $ans2\n\n";

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With warnings, I get errors which look like Argument "" isn't numeric in addition (+) at ./quad.pl line 11, <STDIN> line 3.. Without warnings, of course I don't get these. So, being a competent perl programmer, I want to use warnings, or figure out why I can't. How do I get numeric strings from STDIN?

In reply to negative numeric strings with STDIN by DarknessX

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