3. Charge, in addition to what is paid for hired help, an amount equal to what the proprietor's services would be worth to others; also treat in like manner the services of any member of the family employed in the business and not on the regular payroll.
4. Charge depreciation on all goods carried over on which a less price may have to be made because of damage or any other cause.
5. Charge depreciation on buildings, tools, fixtures, or anything else suffering from age or wear and tear.
6. Charge donations and subscriptions paid.
7. Charge all fixed expenses, such as taxes, insurance, water, lights, fuel, etc.
8. Charge all incidental expenses, such as drayage, postage, office supplies, livery expenses of horses and wagons, telegrams and telephones, advertising, canvassing, etc.
9. Charge losses of every character, including goods stolen, or sent out and not charged, allowances made customers, all debts, etc.
10. Charge collection expense.
11. Charge any other expense not enumerated above.
12. When it is ascertained what the sum of all the foregoing items amounts to, prove it by the books, which will give the total expense for the year; divide this figure by the total of sales, and it will show the percent which it has cost to do business.