You can give $x a type, but prepare to be disappointed. 
> my Rat $x = 0.1;
> $x *= 0.1.FatRat;
Type check failed in assignment to $x; expected Rat but got FatRat (Fa
+tRat.new(1, 100))

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In reply to Re^9: Small Perl 6 discoveries II, Rats by Anonymous Monk
in thread [Perl6] Small discoveries I, __DATA__ by holli

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