Maths homework question

[LomasLongstrider]

Does anyone have any clue if the pattern described works for 7 digit numbers? Did we go wrong somewhere, or did dc and I just waste what felt like a lifetime on a trick question..?

So the pattern seems to be that at some point, the subtraction creates an answer that uses the same digits as the ones input. I tried it three times and always ended up with 954-459=549. At least, that's the only vaguely interesting thing that happened for me.

I imagine it does work for larger numbers, but have no way of proving it and can't think how you would without many, many subtractions!

Sorry I didn't realise this thread posted multiple times .

I'll copy in my follow up posts from the other thread.

"We did 3 digits, and worked out you get the same digits in a later answer as from an answer fron a previous sum, it works for 5 digit numbers too, then we skipped 6 by accident and went straight to 7 so just kept going, but got to 10 sums before we gave up. I was expecting it to take 7 steps, if it could be done, as 3 digits took 3 steps and 5 digits took 5 steps, but we did an extra few just in case.

Also any ideas if it works for 6 digits?"

It did take a fair amount of subtractions in the end, nine seven digit subtractions, and seven six digit subtractions, (as far as we got before giving up), all using carrying over/exchanging and relying on the previous answer being correct, so dc had to backtrack a few times. All to realise it can't be done/is a trick question.

And not forgetting the five digit ones (which weren't as bad as at least it works for those).

A pic of the 5 digit ones.

Ignore where I circled the wrong 63954 etc (fixed now). Dc also added that the pattern seems to keep repeating, which we discovered by mistake.

So not only did I post multiple threads by accident, I just commented on the wrong one. D'oh!

And I did it again .

Ffs, I meant to write dc did nine ten seven digit sums before giving up, sorry after having to carefully check all 26 sums, some multiple times, my brain is fried. How do teachers mark about 30 of these sorts of questions, without going nutty??