c:\@Work\Perl\monks>perl -wMstrict -le
"my $hash;
 $hash->{TGT} = 3335.9999999999995;
 printf '%0.20f', $hash->{TGT};
"
3335.99999999999950000000
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Please see print, printf, sprintf, What Every Computer Scientist Should Know About Floating-Point Arithmetic.