2. You can't prepare a balance sheet with these figures.
3. If your Internet cafe has no other expenses and no non-operating income or expenses, the profit can be calculated like this:
Profit = 10,000 - 4,000 - 3,000 - 1,000 - 300 = 1,700 yuan.
Provided that you identify this consumable as your cost for the month. If it is not your cost this month, but your Internet cafe to add equipment, such as keyboards and mice and so on, can not be counted as a cost, that the calculation of profit in the end do not subtract consumables 300.