Final answer:
The clerk needed to subtract $10 from the total amount owed due to the $10 coupon. Coupons like this are subtracted from the total bill to determine the amount payable.
Step-by-step explanation:
The clerk needed to subtract $10 from the total amount owed at the grocery store because of the $10 coupon. In mathematics, when you have a coupon, it reduces the overall total you have to pay, similar to a discount. The process of deducting a certain amount from another is called subtraction. For example, if Jerod's total bill at a restaurant is $47.50 and he has a $10 coupon, the new total would be $37.50 after subtracting the discount. Additionally, when collecting data on grocery receipts or calculating bills with taxes and tips, subtraction will frequently be used to find the final amount payable. Coupons, therefore, represent a form of monetary value that can impact the final transaction at a register.