How is the Zakat calculated for a fast-food restaurant, and what is a numerical example of it?

Zakat is obligatory on restaurants' income and the value of goods prepared for sale, not on the value of the restaurant itself or its equipment. It is stipulated that the total income and the value of goods prepared for sale reach the nisab (equivalent to 85 grams of gold or 595 grams of silver) and that a complete lunar year (hawl) passes over it. One-quarter of a tenth (2.5%) is to be given as zakat. The value at which the restaurant owner sells is considered. If the restaurant owner possesses cash, gold, or silver that has reached the nisab, then the restaurant's income is considered newly acquired wealth (mal mustafad) and is zakat-eligible along with it. As for debts owed to the restaurant owner, they are zakat-eligible along with his wealth, unless they are owed by procrastinators or those in hardship, in which case zakat is not due until they are collected. Upon collection, zakat is paid for one year or for all years. If the restaurant owner has debts, they are deducted from the wealth, and the remainder is zakat-eligible if it reaches the nisab.