@docgunthrop, I so so appreciate that sort of honesty. Look, you're 1dan on this, I am nothing. Your honest advice, should I just unpublish this Kata given circumstance and given there does not seem to be a nice way of changing/tweaking it? It's a really useful learn for me as well in terms of how I should sturcture a Kata. Thank you! Going out for a bit, will look at reply when back and act on it.

@docgunthrop, okay was thinking about it. Would you suggest I add a further note saying that the product of 2 of the elements in the array must be consecutive to the other element? This then resolves the issue above, BUT I just think its a huge hint. Very happy for any advice on this.

agreed. I was on trading desks - exotic rates and flow credit, and the best in mental math on them, its exactly why I love teaching it in this way. I have taught kids and got their mental math to better than traders at bulge bracket banks using these methods. its slow and might seem a bit convoluted, but it works.

There were 2 things I tried (and clearly to some extent have failed) to force the user to see: how to construct the Head of N5 without really giving the answer away too quickly, and then a very basic property of numbers that between every even is an odd and vice-versa. Really simple ideas but can be leveraged in lovely ways.

@FArekkusu, just 2 basic exmaples of the use of this. eg 77 * 77, use fact that it is 75+2 and all squared and over different Katas user can expand this as a^2 + 2ab + b^2 and note that 75^2 can be done in secs in their head making the problem super simple.

secondly, percent compounds again, can use taylor series and apply ideas from above in slightly unusual way.

If this boils down to a "Why would somebody need this particular knowledge in his life", I think basic mental math skills are as important as knowing how to cook a meal. Just good to have.

Firstly, so sorry on the spoiler I thought people can click it if they want to but you flag a spoiler if it has solution stuff in it. Was not in any way trying to be deceptive. OKay, will read rest of your reply now and think about it but just wanted this noted. Thank you.

Okay, the next thing on "explain the idea to your students in the classroom, but you don't explain the idea to CW users." I thought I did guide the user in the hint note.

Look dude, I tried to create a Kata to guide the user into spotting a specific algorithm but clearly have not done in a way you find satisfactory. All I can do is apologise for this. I didn't spend my time to go out of my way to annoy you, I tried to create something which would teach something and at least at the end of spotting the pattern ahve the user asking themsleves but WHY does that work? And then the next Kata would have demonstrated it in a more general class of problems.

And wrt programming learning- I thought this required use of strings potentially and if then else constructs which is nice practice. Again, you disagree and given your welath of experience over mine, I can just accept your view and learn from it.

sorry did not see your reply before writing mine, also- kata is published again, just wanted to check something in it. can you let me know solution method. super interested in it? thank you!

also, your pt above on not being clear on relationship between and 2nd and 3rd- yeah man, I deliberately did not want to and tried my hardest to construct the kata in a way where I did not have to be explicit on this but for user to HAVE to spot it themselves. For me, giving them that relationship gave the game away and made it super simple. I might have to though- let me know your thoughts.

Sorry @ducgunthrop to be clearer, I don't understand how @FArekkusu would have got 56 in the above (I know that was the example) but the point is, no multiplication in any way should be used. If you don't use multiplication in any way to get the factors of the head of N5, I thought (and possibly incorrectly) that my solutions were the only logical ones. I am just waiting for @FArekkusu to clarify method used to get the above. Hope this clears up issue, and is reason why I am not clicking issue resolved. I just am really interested in method used. Thank you.

Hi @ducgunthrop, I honestly did not hide anything. Just replied as normal. I asked above " Do you mind me asking your method used? Just really interested @FArekkusu to see how you got those out." just waiting for a reply, and can then figure out method and accordingly may update notes on the kata with the note shown in above reply "Note- I could've given them a hit of the relationship between the output entries BUT I thought that gives the game away."

Just fixed, silly thing. Thank you for spot.

Hi @Farekkusu, apologies for delay in reply, just had some work to do.

Okay, I am very sorry to have offended you with this Kata. Its honestly quite a powerful method that once a bit built up on can allow someone to perform pretty large mental calculations very quickly. I show them a simple pattern in this Kata and establish the proper rules later on to explain WHY it works. I've done it in classrooms to huge success and wanted to translate it into an online JS kata series, admittedly, I may have failed a bit in doing so, but any constructive criticism I am very happy to recieve. Sincerely sorry to have annoyed you once again.

I understand the limitations/constraints in the Kata seem onerous but without them, there really is no way I could think of to force the user to learn what I want them to learn from this Kata.

Thank you again for your time.

just added more random tests in both groups, 50 in each. and also ensured sample tests inc numbers ending 0 through 9. Thank you.