Help with accounting: finding errors

Over the years, accountants and people in business offices have found that things don't always balance. When working with adding machines, columns of figures, computer keyboards, and just handwritten numbers, the possibility of error is great.

People who need to have their figures balance and be accurate have found that many errors have little tip-offs. Common errors follow recognizable patterns. Experienced accountants know these patterns; when things don't work, they look to see what the difference is and go from there. If you know what kind of error was made, you'll have a much easier time tracking it down.

Here are some of the patterns and what to do about them.

1. When the difference--the amount you are out of balance or off from the expected total--is evenly divisible by 9, you have a transposition error.

First, how do you tell if it's evenly divisible by 9? You could go to a calculator and divide by 9 and see if there's a decimal portion in the answer, but that's a lot of work. There's a shortcut method. Take the digits of the number you want to check and add them together. If the result has more than 1 digit, add those digits together until you get a single digit. If that single digit is 9, then the number is evenly divisible by 9. If it's anything other than 9, the number is not evenly divisible by 9.

Example: Is 81 divisible by 9? Add 8 plus 1 to get 9. The answer is 9. It is divisible by 9.

Example: Is 17,514 divisible by 9? Add 1 plus 7 plus 5 plus 1 plus 4; the answer is 18. That's still more than one digit, so add these two digits together. Add 1 plus 8 to get 9. Yes, 17,514 is evenly divisible by 9.

Example: Is 17,520 divisible by 9? Add 1 plus 7 plus 5 plus 2 plus 0; the answer is 15. That's still more than one digit, so add these two digits together. Add 1 plus 5 to get 6. No, 17,520 is not evenly divisible by 9.

Second, what is a transposition error? A transposition error happens when you reverse two digits in a number or leave a zero off the end of a number. Both are extremely easy to do. Transposition errors always result in differences divisible by 9.

Example: If you should have written (or entered into your adding machine or computer) 672 but you accidentally wrote 762, you have made a transposition error. The first two digits are reversed. The difference (762 - 672) is 90. Check to see if 90 is divisible by 9. That one is obvious; it is.

Example: If you should have written 880 but you accidentally wrote 88 (leaving off the final zero), you have made a transposition error. The difference (880 - 88) is 792. Check to see if 792 is divisible by 9. Add up the digits as explained above; you get 18. Add those two digits (1 and 8) together to get 9. It is divisible by 9, as all transposition differences are.

2. If the difference is 3 or 30 or 300 or 3000 (off by 3 in one column only), chances are that you've made a ten-key error. That's because each key on a ten-key pad is exactly 3 higher than the key immediately below it. Thus, if you reach for the 1 key but go a little too high, you'll hit the 4 key. Difference? 3 or 30--depending on which column contains the error. You can be high by 3 (or 30, etc.) or low by 3; each is usually the result of getting the key on the wrong row.

If you are working with debit and credit columns and totals, you have two more techniques available to quickly locate errors. Compute the difference--the amount you are out of balance.

3. First, look through the listing of figures you were balancing to see if you can locate the exact amount of the difference. This would occur if you merely left out a number when adding or posting the figures. If you find the exact amount, you've found the error.

4. If that fails, divide your difference by 2. Check your listings of figures or balances for that number. If you add or post a number in the wrong column (as a debit when it should be a credit, or vice versa), your difference will always be double the amount that you put in the wrong column. If you find this half-the-difference figure, it's probably in the wrong column or you've added when you should have subtracted (or vice versa).

Knowing these little markers of common errors can save a tremendous amount of time in locating accounting errors.