OP solved it, closing

Not a kata issue. Also, your code should return the array of original unmodified string instead of the change-cased one in which you use for comparison with values in dictionary.

Your code fails for cases like n = 225 because it is divisible by 9, resulting in 25. However, there is no decimal point in 25, so p now becomes [25] (an array of string) due to splitting. Trying to access a non-existent index (1) results in undefined, and trying to access undefined[0] results in the Error.

The user's already solved the kata.

Not an issue.

Not an issue.

You'd have a whole other problem if your list is empty other than reduce here using strictly list.length as the denominator.

Thanks I forgot about fractions

There are also non-integers.

I am trying to understand you answer but I don't see how it is working.
Can you explain it please?
I always look at other answers after I solve a challenge to see how people solve the code with less lines, i've learned a lot looking at other people's answers. But I don't understand yours

Object.values doesn't exist in CW's Node 6 version (it's a ES7 thing).