Simon is working out a math problem looking for a nine digit number in which the first two digits firm a number divisible by 2, the first three digits form a number divisible by 3, the first four digits form a number divisible by 4 and so on, the whole number being divisible by 9. There is only one answer to this problem if one does not use zeros as digits.
Inspired by a SingingBanana Channel video.
Geeks out of the box 