Reading 1

Unit 7- Reading 1

Page 98

Bar codes

Look at the items you have purchased recently. Do any of them have a bar code on the package? A bar code is a printed pattern of black and white lines. The pattern contains important information.

Bar codes are becoming common all over the world. The technology is especially useful in supermarkets.

NEED FOR BAR CODES

Before bar codes were invented, supermarket customers waited in long lines. They waited for a clerk to add up the cost of their purchases. First, the clerk picked up an item.

Then she searched for a price sticker and read the amount. Finally, she entered the price on a cash register. Sometimes the clerk did not read the price accurately. The checkout process was slow. Bar codes were invented to help grocery stores speed up the checkout process. Now a clerk picks up an item and passes it over a scanner.

The scanner reads the bar code. The store computer searches its memory. It finds the matching bar code. Then it automatically enters the correct price into the cash register.

HOW BAR CODES WORK

A supermarket computer system has in its memory the bar code for each item in the store.

The computer also has in its memory the price of each item. If a store has a sale on canned fruit, for instance, the store manager does not have to change the prices on the cans. Instead, he changes the price in the computer memory. When a sale item is scanned, the computer reads the bar code. It enters the new price into the cash register.

Bar codes also help stores count what they have sold. As items are scanned, the computer automatically counts them. At the end of each day, the store manager knows what the store has sold. For example, he knows that he still has enough canned fruit, but that he must order more coffee.

HOW BAR CODES DEVELOPED

Bar code technology became available in 1974.

Since then, several bar code systems have been designed. Each system is based on creating a unique identification number for every manufacturer. One system uses 12-digit identification numbers. Each printed bar code consists of a unique pattern of black and white lines that represent numbers from 0 to 9. The first six digits identify the manufacturer. The next five digits identify a certain product.

The last digit is called a check digit. It tells if the number scanned correctly. For example, the Campbell Soup Company produces canned foods. The first six digits of all Campbell products are the same. The next five digits are different for each Campbell product, such as chicken soup, tomato soup, and so on. As a result, the bar code, for each product in a store is unique.

HOW BAR CODES HELP

Many kinds of businesses use bar codes. However, a bar code system is especially useful in supermarkets. One reason is that most customers purchase a large number of items. Bar codes make the checkout process fast and easy. Also, supermarkets sell a wide variety of items. Most of these items sell quickly.

Using bar codes allows stores 10 easily track what has sold and what needs to be ordered. Using the technology of bar codes makes supermarkets more efficient.