Are you ready for another number?

Do you think it will further confuse, complicate or aggravate your life?

No, according to local officials at Safeway Stores Inc., who are installing Approvacheck in select area stores.

As if the complexities of the modern world were not taken care of with numbers for social security, 24-hour computerized bank tellers, savings accounts, checking accounts, credit cards and the impending nine-digit ZIP code, seven stores in the Washington metropolitan area are insisting customers have another number if they want to pay for food by check.

Over the past four years carefully selected Safeway stores nationwide have installed the computerized check approval system to eliminate the waiting time spent when checks were approved manually by store clerks and managers. Last week the Georgetown area Safeway became the 65th store in the country to install the system.

The first system in the area appeared in 1977 for use in four stores.

"The [Approvacheck] computer is a timesaving device to assist in productivity," said Larry Johnson, assistant public affairs manager for the Safeway, Washington, D.C. Division "and will not affect the price of goods or cause employes to lose their jobs."

Also intended to cut down on bad check passing when the system becomes centralized by region, it requires the user to have a number of up to 16 digits that is punched into a small computer terminal with a keyboard comparable in looks to a push-button telephone. The Georgetown Safeway has three permanent terminals to handle its heavy flow of customers, whereas other stores in the area have one.

After a password of one to six digits and a store-assigned number have been plugged in, the terminal imprints the store number on a check inserted in the machine's thin slot -- if none of the customer's previous checks have bounced. Otherwise, the words "See manager" appear on a small screen.

One computer installation can hold one million names on file. It replaces the old system under which store personnel kept cards certified by local banks and had to thumb through them to check a consumer's record.

Though some customers balked at having to memorize a "cumbersome" number or refer to it on their personalized card, an assistant manager at the Georgetown location, Stuart Lee, insists the system is more convenient and efficient, making smoother store operations possible.

Some customers, however, find this difficult to believe. "I think it's an outrage," said a middle-aged man who says he is writing a book on computers. "All they're doing is saving money by reducing clerks, they're not saving us time."

Still other customers say they regret the loss of the personal touch at their stores, preferring the informal "Do you have an account with us?" to the impartiality of a computer.

Joesph Douglas, national sales manager for Approvacheck Corp. of Massachusetts, says use of the system has psychological effects that could boost sales for the stores. "The very fact that a customer has check approval will induce him to buy something extra instead of waiting until the checkout counter where his check may be turned down," he says.

Safeway's strongest competitor, Giant Food Inc., has an electric check approval system attached to its "scanner" checkout machines that automatically tally and price items as they are moved across a small glass window. Giant began installing its system in 1975 when converting to the scanner system and the firm has a centralized file bank in Landover, Md., for every store in area. The computer system approves checks at the same time customers pay.