I've known about the number 9 thing for some time, but what does “transposition” mean in the accounting biz?
If you are adding up a list of numbers, for example credit card receipts, and you have a computer total and the two don’t match, you subtract one from another and if the difference is evenly divisible by 9 you’ve transposed a number in the list. Or someone keyed the credit slip backwards.
Like adding 54 instead of 45.