The computer cannot accurately store 1/10 since it's a periodic number in binary (just like 1/3 is periodic in decimal). 

>perl -e"printf '%.16e', 0.1"
1.0000000000000001e-001
                 ^
                 |
                 |

[download]

Avoid the accumulation of error: 

for (0..89) {
   my $i = $_ / 10;
   print "$i\n";
}

[download]

Update: and/or round your results.

In reply to Re: for loop with float by ikegami
in thread for loop with float by RobertCraven

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