use warnings;
use strict;
use bignum;

sub trim
{
    my $number=$_[0];
    my $no_d_p=$_[1];  #number of decimal places
    die "$number is not a number" unless &isNumber($number); #check that you've got the right input
    die "$no_d_p is not an integer" unless int($no_d_p)==$no_d_p;

    my $power=0;   
    for($power=0;$number<=(10**($no_d_p-1));$power++){
        $number*=10;
    }   
    $number=int($number);
    $number/=(10**$power);      
    return($number);
}

sub isNumber
{
   my $number=$_[0];
    if ($number !~ /^\-?\d+(?:\.\d+)?(?:[Ee][+-]?\d{1,3})?$/){
	return 0;
    } else {
	return 1;
    }
}

my $e = 0.00141;
my $o =1;
for(my $r=0; $r<=10; $r++){
        $o *=$e;
        $o=&trim($o,5);
        print "$o\n";
}


exit 0;

##</code><code>##

0.00141
0.0000019881
0.0000000028032
0.0000000000039525
0.000000000000005573
0.0000000000000000078579
0.000000000000000000011079
0.000000000000000000000015621
0.000000000000000000000000022025
0.000000000000000000000000000031055
0.000000000000000000000000000000043787