Ok Goron I brought the int function up sooner to get rid of the floating point asp. And to remove decimels from the addition portion. Seen in this code based of yours.

Code

use strict;

my $number = 12650 / 10000;
#my $number = 1.265;
my $dp = 2;

print "Actual: $number\n";

my $exp = 10 ** ($dp+1);

my $val1 = int($number * $exp);
my $val2 = $val1 + 5;
my $val4 = $val2 / $exp;

print "val1 = value x exp = $val1\n";
print "val2 = val1 + 5 = $val2\n";
#print "val3 = int(val2) = $val3\n";
print "val4 = val2 / exp = $val4\n";
[download]

Output

Actual: 1.265
val1 = value x exp = 1265
val2 = val1 + 5 = 1270
val4 = va2 / exp = 1.27
[download]

Ok I messed it up if you use 1200 you get 12.05 so I think you need to do it in steps throwing away un needed decimals. Oh well need to catch a train will play with it tonight because it is not Internet Explorer and I need something that is not Internet Explorer.