It's not really about string representation or integers. It may be more about the limits of Perl 5 and most programming languages in dealing with fractions and floating point. For example:

perl -Mstrict -w -e 'if (0.3 == 0.1 * 3) { print "equals\n" } else { p
+rint "* difference * ", abs(0.3 - 0.1 * 3), "\n" }'
* difference * 5.55111512312578e-17
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