I think I might have found something… I don’t know, tell me what you think, anyway

For example:

6529 = 8000 – ????

I first round up the last 3 digits of 6529  (= *529), which is the number of zeros of 8000 (3 zeros, so 3 digits)

9 + 1  = 10 ;   1

2 + 7 = 9    ;   7

5 + 4 = 9  ;    4

Then, for 6 (of 6529) and 8 (of 8000), I think I have found a rule.  If the numbers differ in 1, then it’s “0”; if the numbers differ in 2, then it’s “1”; if the numbers differ in 3, then it’s “2”and so on This is what I mean:

6529 = 7000 – 0471

6529 = 8000 – 1471

6529 = 9000 – 2471

6529 = 9000 – 3471

Furthermore, this rule applies to the problem of my question on the post above. The one of   “ 5492 = 8000 – #    ”

Between 5 (of 5492) and 8 (of 8000), they differ in “3” so it would be “2” the first number of the answer. So,

5492 = 8000 – 2508

Tell me what do you think and if you have another method for this 🙂