You mean something like this?

perl> sub distribute{ 
    my $weight = shift;
    my $n = int( $weight / 70 ) +1; 
    return ($weight /$n) x $n;
}
perl> print "$_ as ", distribute $_ for map{ int rand 250 } 1 .. 20;;
65 as  65
130 as  65 65
91 as  45.5 45.5
93 as  46.5 46.5
243 as  60.75 60.75 60.75 60.75
15 as  15
79 as  39.5 39.5
235 as  58.75 58.75 58.75 58.75
119 as  59.5 59.5
105 as  52.5 52.5
37 as  37
42 as  42
75 as  37.5 37.5
119 as  59.5 59.5
79 as  39.5 39.5
225 as  56.25 56.25 56.25 56.25
180 as  60 60 60
104 as  52 52
183 as  61 61 61
118 as  59 59
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