my $BigCalc;
{
my $SmallCalc;
....
$BigCalc = f($SmallCalc);
}
...
DoSomething($BigCalc);

##</code><code>##

#!/use/bin/perl
use warnings;
use strict;
{
    my $x = 1;
    print "small calc $x\n";
}

BLOCK: {
    my $x = 2;
    print "small calc $x\n";
}
do {
    my $x = 3;
    print "small calc $x\n";
};

if (1) {
    my $x = 4;
    print "small calc $x\n";
}