Britons plug in Bombay computers

Thanks to the ancient Hindu practice of mathematics, the streets of Detroit are a little safer today.

Yes, and power plants run better in Iran, American Express processes credit card bills faster, and some of Britain's petrol stations operate more efficiently.

The Hindu connection for these enterprises lies in one of India's fastest-growing industries: computer software.

Despite the country's massive poverty, India educates a surplus of scientists and engineers, many of whom are forced to find work in the West. (India claims the third-largest supply of scientists and engineers behind the United States and the Soviet Union, although Japan may now be a close contender.)

India now employs more than a thousand software experts, and expects the number to grow to 15,000 by 1985. Its computer software exports are growing an estimated 25 percent a year, and its domestic market 15 percent.

Why India? ''Because we are abstract thinkers,'' says F. C. Kohli, director of Tata Consultancy Services, which commands nearly 80 percent of India's software business.

The mental agility of working with numbers and ideas which is required in computer programming, and in the use of computers in management systems, fits well with Indian tradition, Mr. Kohli says.

One history book on India states: ''Hindu mathematics is undoubtedly the finest intellectual achievement of the subcontinent.'' Indian mathematics discovered zero, pi, and square roots. One ancient math whiz said he knew the positive integers ''as personal friends.''

Since 1974, India has been exporting software expertise to the world. Tata Consultancy, for instance, helped the Detroit Police Department improve its data collection for crime detection.

One $500,000 TCS contract, which beat out an American software competitor, revamped the accounts receivable operations for the American Express Company in Latin America. TCS also linked up with Japan's largest computer company, Fujitsu , to assist clients in Australia.

TCS, which employs more than 500 computer specialists and management specialists, also performs systems analysis for clients as well as programming. Because of India's low wage structure, low standard of living, and other cost benefits, Tata can undercut competitors' prices by about 15 percent, Kohli says. Salaries of $250 a month are not uncommon. The average age in the firm is 26 years, and about 20 employees hold PhDs. Some 70 workers have returned from foreign companies and universities, a sort of reverse ''brain drain.''

India's drive to be self-reliant in most technologies has kept it from developing a strong computer industry within the country. It has only about 1, 000 computers at present.

TCS's sister organization, Tata Burroughs, is assembling computer equipment for sales abroad and at home. But tight import restrictions on computers, imposed in hopes of developing an indigenous industry, moderates the industry's growth. Import duties run as high as 180 percent.

One setback was the withdrawal of International Business Machines from India in 1978 when it refused to consent to India's demand that IBM dilute its 100 percent equity holding in an Indian subsidiary. ''We will definitely feel the loss of IBM in India,'' Mr. Kohli says. In fact, Tata must send its people to New York for training on IBM equipment.

Another problem is constant charges that computers will eliminate jobs in teeming India, a complaint common in the West 20 years ago.

''Computers don't throw people out of jobs,'' counters Kohli, ''because people are changing jobs all the time anyway. Technology creates a lot more jobs than it takes away.''

IBM may gain entrance to India again. The World Bank is insisting that an IBM system be used to improve the Indian railways. The government insists it can provide the same system. If IBM wins, it might be able to operate in India through an intermediary company.