Be Excellent To Each Other

Click.

The poxy woman has got it correct every time for me!

What's going on?

I realise the explanation will suck all the fun out of it, but I'd still like to know. I could Google it of course, but would much rather have it explained in plain words.

ok, any number = (a*10 + b), i.e. with 47, a = 4, b = 7
number - b always = a multiple of 10...
You;'re saying '47 minus the units (which is 7)' - so must be 40.
Then take off the first digit (so 40 - 4 = 36).. well, a multiple of ten by definition is a number times 10...
Take that number away once, and (10-1=9) you have a multiple of 9!

So, any number you pick and 'subtract the digits from ' will always give you a multiple of 9.
All the multiples of 9 on the grid are the same gift (tho each time you run it it changes what that square is), but whatever is on 9 is also on 18, 27, etc.

Simples!

Ta!

See I knew it would be some maths jiggery-pokery going on, but I can never get my head around such things.

You can explain everything with Scientology.

I hope I have not become infected with Scientology-ness, by taking part in that quiz thing.