perl - perl6/rakudo: How can I change the data-type of a variable? -

#!perl6 use v6;  $m = 70; $n = 30;  ( $m div $n ).say; 

the first examples works, second doesn't. suppose it's because in second example variable-values strings. if guess right, how change string-variables integer-variables?

#!perl6 use v6;  $m = '70'; $n = '30';  ( $m div $n ).say;   # no applicable candidates found dispatch 'infix:<div>'.  # available candidates are: # :(int $a, int $b)  #   in main program body @ line 7:./perl5.pl 

you can manually cast int

( $m.int div $n.int ).say; 

actually have hoped prefix:<+> work in

( +$m div +$n ).say; 

but "num"ifies , sig requires "int", not sure if should way or not.

update: +$m works.