some notes

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diff --git a/challenge-143/james-smith/README.md b/challenge-143/james-smith/README.md
index d7d0f3e04a..fc9a9a857d 100644
--- a/challenge-143/james-smith/README.md
+++ b/challenge-143/james-smith/README.md
@@ -18,6 +18,22 @@ https://github.com/drbaggy/perlweeklychallenge-club/tree/master/challenge-143/ja
 
 ## The solution
 
+The simple solution is just to "`eval`" the string, but where is the fun in that... We can either go for a tokenizing parser - where we create an array of elements brackets, symbols, numbers, or we can use regular expressions to reduce the equation.
+
+All students will remember BODMAS - Brackets, order, Division/Multiplication, Addition/Division. (or BIDMAS, PIDMAS, PEMDAS or whatever you used to remember it). So we have to break our prasing down into:
+
+ * Brackets
+ * Order    - we don't have this in our equations
+ * Division/Multiplication - we only have the latter
+ * Addition/Subtraction.
+
+So our logic becomes:
+
+ * Find brackets without brackets within - for these we evaluate the contents using the same algorithm;
+ * If there are no brackets left - we then looking for multiplications from left to right and evaluate these.
+ * If there are no brackets or multiplications we look at the addition/subtraction again left to right.
+ * This gives the following perl function:
+
 ```perl
 sub evaluate  {
   my $str = shift;
@@ -28,12 +44,20 @@ sub evaluate  {
 }
 ```
 
+For small strings - this is about the same speed as `eval`, for larger strings not so, but in both cases it is "safer" as string `eval` of "tainted" input is a real security risk.
+
 # Challenge 2 - Stealthy Number
 
 ***You are given a positive number, `$n`.  Write a script to find out if the given number is Stealthy Number. A positive integer `N` is stealthy, if there exist positive integers `a`, `b`, `c`, `d` such that `a * b = c * d = N` and `a + b = c + d + 1`.***
 
 ## The solution
 
+First we find all the factors of `N` (well the ones for where `N=a*b` and `a<b`)
+
+We then store the sum of the factors in a hash (as the keys), we also store the sum of the factors + 1 in the hash {using `++` so what is stored is the count of these numbers}.
+
+So if we have the condition `a+b == c+d+1` is equivalent to seeing which keys in the hash have a value greater than 1. In which case we have our value. For the problem we don't need this value - just whether there is a value. So our function comes down to this.
+
 ```perl
 sub stealthy_number {
   my($n,%c) = shift;