Thus the figures in the last column indicate the difference between the figures of the original item.

(b) If the difference is divisible by 9 and consists of two significant figures followed by one or more naughts, the error may be caused by a one-column transposition between columns of a higher order. For instance:

The correct amount being6,394
and the transposed amount  3,694
the difference is2,700

which divided by 9 gives 300. This indicates a transposition between figures in the “100” and “1,000” columns, the difference between these figures being 3. Reference to the example given will show this to be the case.

(c) When the difference between the trial balance totals is divisible by 9 and lies between 99 and 1,000, the error may be due to a two-column transposition. Here the middle figure of the error is always a 9, e.g., an error of 297 resulting from writing 512 as 215. Dividing the number (27) formed by the two outside figures of the difference by 9, the quotient (3) is the difference between the two transposed figures, i.e., the 5 and the 2. For instance:

Correct
Number 		Transposed
Number		 Difference
51441599 9 divided by 9 = 1
73553719818 ”  ” 9 = 2
98118979272 ”  ” 9 = 8

Thus, the figures in the last column (1, 2, 8) indicate the difference between the two transposed figures in the correct item. Instead of dropping the middle figure of the difference and dividing by 9 as above, the entire difference figure may be divided by 99 with the same result.

(d) Similarly, when the difference is 999 or a four-figure amount with two 9’s in the middle, a three-column transposition may be indicated thereby. For instance:

Correct
Number 		Transposed
Number		 Difference
5,1744,1750,99909 divided by 9 = 1
6,3922,3963,99636 ”  ” 9 = 4
7,0811,0875,99454 ”  ” 9 = 6

the figures in the last column (1, 4, 6) again indicating the difference between the transposed figures in the original.