B&B's operating gross profit margin adopts operating gross profit amount/main business income X 100%. According to relevant information, the operating gross profit margin is the ratio of operating gross profit to main business income, and its calculation formula is: operating gross profit margin = operating gross profit/main business income X 100%. Operating gross profit margin is used to reflect the gross profit of an enterprise per yuan of operating income and is the basis of net profit. Operating gross profit margin is used to analyze the profitability of enterprises.