NUMBERS ARE an integral part of our lives from before birth until after death. Numbers can tell us what the odds are of having a child, and the odds of its surviving; they can be used to predict when we are apt to die. We use numbers to compare ourselves and our lives with the lives of other Americans and of people in other countries.

There are problems in obtaining accurate numbers. Many countries simply don't have adequate statistics, particularly in the less developed world, where rulers often don't know how many people they rule. Other countries have statistics but withhold them. The basic data and tables used here have come from the major industrial countries which produce accurate, roughly comparable facts. They are: Australia, Austria, Belgium, Britain, Canada, France, West Germany, Ireland, Italy, Japan, the Netherlands, Norway, Denmark, Sweden, Spain, Switzerland and the United States . IF YOU WORK in New York and your boss tells you you're being transferred to Germany with a 30 percent increase in salary, don't celebrate -- consider quitting instead. Your standard of living will drop by 29 percent.

That's what's shown in figures compiled by the United Nations. Its professional lifestyles cost-of-living index, used to determine salary rates among U.N. professional and supervisory employes all over the world, is different from most cost-of-living ratings.

A normal cost-of-living index is generally more accurate for low-income families and is based on a limited number of basic cost factors (meat, bread, etc.). Not so the U.N. data; it's based on secomparable 300 items for each of the organization's 164 countries. The expenditure on those items (the kinds of things an upper-middle-class family of three buys) is researched among the U.N. staff.

All living standards are expressed in one currency -- U.S. dollars -- then adjusted for local currency fluctuations, so the index deals with comparable data. The figures are reviewed and are adjusted no less than three times a year. Those at hand are for the end of June 1978. For convenience they're indexed to New York.

New York is much cheaper than 11 other major cities. Only Dublin, Rome and Montreal are less expensive when you take in decent rented accommodations, public transport, gasoline, automobile costs, liquor and other items. A combination of high salaries and comparatively low living costs have combined to produce the comfortable much-envied "American way of life."

In the Common Market's headquarters town, Brussels, you'd need 61 cents added to every dollar you earn today just to stand still. In Geneva, you'd very nearly have to double your salary to stay level, while in Tokyo you'd need $21,000 to equal a $10,000 New York salary's purchasing power.

The two real bargain cities of the world are Moscow and Colombo, Sri Lanka (formerly Ceylon). Accommodations are a large part of the equation, at least in Moscow, where rents are lower, even if you don't get to choose your apartment.

THE PRICE OF FOOD also varies greatly from country to country. And it doesn't always differ as you'd expect.

Americans have always eaten a lot of steak, but an even better place to go for steak is Australia. There sirloin in 1976 cost 94 cents a pound.Along with the Portuguese and the Canadians, we have to pay to pay around twice the Australian price. Our steak then averaged around $1.97 a pound. In Japan, a pound of sirloin would have set you back $7.75 a pound.

If you can't eat steak, how about fish? It's a similar story in Japan where fresh fish costs an average of just $4.92 a pound. That's almost twice what it costs in Portugal and Italy -- the next most expensive countries.

For good, inexpensive fish, head for Holland, which had the cheapest fish of any of the studied countries at 72 cents a pound. Denmark was No. 2 at 81 cents. Although fish was reasonably inexpensive in Britain, at $1.32 a pound, it was even cheaper in Austria at $1.13.

A good general indicator of relative food costs is the price of a major source of calories in most countries -- bread. Portugal was the least expensive country for bread at 15 cents a large loaf. Ireland came in as low as 40 cents a loaf. Sweden, on the other hand, was worst off, with bread at $1.34 a large loaf.

Milk, eggs and cheese are staple ingredients in most North American diets. In the United States in 1976 we had to pay, at 23 cents a pint, more than most other people for our milk, yet we also drink much more. Our cheese is only slightly more expensive than the average. Switzerland, Germany and Italy pay much more. Finally, our eggs are among the world's most reasonable.

AS FOR TAXES, American rates are about average, although married couples with children are given more tax credit than in some other countries.

The Danes have the worst deal. In Denmark, single people turn over an average of 43 percent of their paycheck. A Dane earning $100 a week would take home only $57.

Next highest taxes are in Sweden, then Holland. West Germany and Norway run a close fourth place. Britain, where everybody complains about high taxes, is sixth, with a single-person tax rate of 31 percent.

In Spain, a single person pays only 7 percent of his total earnings. But he doesn't get a tax break if he's married with two children. The Italians have the second-lowest tax rates. Single people pay only 12 percent of their wages, but also get no relief if they're married with two children.

What We Do After a Hard Day's Work

WHAT DO YOU like to do after a hard day's work? Your answer may well depend on your nationality. Our culture has a strong influence on how we unwind.

When Americans a few years ago were asked by Gallup how they like to spend an evening, a staggering 46 percent opted for the television set.

In the United States, we have 571 television sets for every thousand people; about 1.7 people to every TV set. That's a lot of two- and three-set families. We have more color sets, more channels to choose from and more hours of programming.

The Canadians come second with one set for every 2.7 people, closely followed by the Swedes with 2.8. Next comes Britain -- one for every 3.1 people.

Even in Spain -- which has the lowest number of sets of any of our studied countries -- you're never far from a TV. There are about 5.7 Spaniards to a set.

While 38 percent of Americans interviewed by Roper last year said that TV was of great interest, an even larger number -- 43 percent -- said they were very interested in sports. Only 3 percent claim no interest whatsoever in television; even more people -- 15 percent -- say they have no interest in sports.

After sports and TV, Americans' favorite ways to unwind are by listening to popular music, not rock but "easy listening" music -- what Frank Sinatra and Andy Williams do well. Forty-four percent of us show high or moderate interest in the theater.

The five areas in which the fewest Americans have a high degree of interest are classical literature, ballet and symphony (tied at 7 percent), modern art (5 percent) and opera (4 percent). Higher up the scale, the 11 percent high-interest mark is jointly shared by detective-story readers and modern-dance lovers.

The Italians -- at 25 percent Europe's most dedicated television addicts -- are also Europe's most gregarious nation: 18 percent gave socializing as their preferred way of enjoying themselves.

Americans and Spanish aren't far behind in liking parties and visits with friends -- 16 percent and 17 percent respectively. In Britain, a mere 7 percent ranked socializing high on their list of favorite activities.Nearly as many prefer puttering about at home. The French come out on top of this puttering-about category with 7 percent.

The French, Austrians and West Germans are the most active people. One out of 10 in these countries lists a participant sport as his or her favorite diversion.

AMERICANS ARE the most film-fixated people in the world. We've got nearly 17,000 movie theaters, with a total seating capacity of over 7 million. That means we could take the entire populations of Norway and Ireland to the movies on a rainy day.And that's not even counting our 4,000 drive-in movies.

Britain has just over 1,500 movie houses, with a capacity of nearly 1 million. That's about average for the list.

The figures for seating capacity per thousand population show Spain at the top of the list, with 74 movie seats per thousand population. Next comes Belgium, with half that proportion, then Australia and Norway. The Japanese have no more than 10 seats per thousand population. And the British have a meager 17.

But the United States, for all its 17,000 movie theaters, has just under 30 seats per thousand.

If we're the most film-fixated people in the world, it follows that we go to the movies the most often. Wrong. The Italians go twice as often as we do. And the Spanish go three times for our every two visits. In Britain, the average person sees an average of only 2.5 films each year.

The Japanese have the distinction of seeing the least number of films a year -- just under two. This is peculiar because, with an output of 405 feature pictures a year, they make twice as many films as the Italians, and nearly three times as many as we do.

France, not the United States, comes after Japan in film-making with 234 films in 1974. In Italy, in 1975, they made over 200. The United States ranks a poor fourth.

In Britain, where the film industry is said to be in bad straits, they still made 70 films for exhibition in cinemas during 1975. Ireland is at the bottom of the list -- only two films in 1975.

The Houses We Live In

ALTHOUGH HOME can be anything from a 50-room chateau to a tin shack, people around the world generally live between these extremes. Most homes in most countries have four or five rooms. Canada is an exception: the highest proportion of Canadians live in a seven-room houses.

In France more than 11 percent of the population lives in a one-room dwelling and more than 20 percent in two-room dwellings -- a figure beaten only by Denmarmk's 22.5 percent.

In the United States, 64 percent live in a house of our own with at least a bit of land. Only four people in a hundred live in an attached (row) house. Only 28 percent of us are apartment-dwellers.

In Britain, almost three-quarters of the population live in one-family houses, and less than a quarter in apartments. Fifty percent of British houses are attached and 23 percent detached.

France tops the table for apartment living, with 78 percent. In Japan, three-quarters of the people live in individual houses. And the figure for the crowded Netherlands is 58 percent.

You'd expect the United States to be a world leader in building new housing. That's not the case: We're behind most other nations. Japan is tops, with 18.7 new houses per thousand population. Our figure is 9.4. Most European countries build more new homes relative to population than we do.

Japan takes the prize for recently built houses: 78 percent of their homes were built after World War II. The oldest housing (51 percent) is in France, where more than half the homes are pre-World War I, and Ireland (45 percent).

AFTER A ROOF over one's head, what else is required? Perhaps the most important -- and basic -- facility is running water.

In Austria, Belgium, France and Italy, more than 90 percent of all households have piped water. At the bottom of the list are Ireland and Spain, with 86 percent and 68 percent.

How about a bathtub or shower stall? The top countries in such facilities are Canada, Australia, the Netherlands and Sweden -- where 98 percent of all households have a fixed bath or shower.

In the United States, four in every hundred households do not have bath-tubs or showers. Some 36 percent of all Belgian households have no fixed bath or shower, 33 percent in France and Austria.

Another essential is a flush toilet. Only five countries in our study have less than 90 percent of households with flush toilets: Spain, Ireland, Norway, France, Japan. Even these countries have figures of over 70 percent -- with the exception of Japan, where 35 percent of the households have flush toilets.

ELECTRICITY is almost universal in the developed countries, where more people have electricity than running water. Ninety-nine out of every 100 households have electricity in all but three of the studied countries. The exceptions are Spain (96 percent) and Ireland and Japan (98 percent).

Ninety-nine percent of the households in the United States and Canada wouldn't be able to cope without a refrigerator. In Australia it's 96 percent.

But in Britain, only 85 percent have fridges and, in Norway, the figure is 84 percent.

In Japan more than one in four households does not have a refrigerator.But the lowest country on the list is Ireland. Only 49 percent of Irish households have a refrigerator.

After the refrigerator, the next home essential is the washing machine. The Dutch head this list, with 85 percent of the households with a washing machine. The West Germans run a close second at 84 percent. In the United States, 83 percent have one.

Britain is about average on the washing-machine list at 71 percent. Lowest of all is Switzerland, where half the housewives send laundry out or wash it by hand.

It's surprising how many households still don't have telephones in some of the most communications-sophisticated countries in the world. In the United States, only 70 percent of all households have a telephone.

In Canada, there are telephones in 57 percent of all households. Britain is about average with almost 40 percent. The French are low at a mere 26 percent. Ireland is lowest of all at 14 percent.

AMERICANS are the worst-read people of all the nationalities surveyed. In the United States, three-quarters of all adults seem to not have read a book from one year to the next.

Our nearest rivals as nonreaders are the Italians. Only a third of them ever read a book from cover to cover. There's a bit more interest in Spain, where 48 percent read books.

The best-read people on our list are the Swiss. Only 19 percent fail to read at least one book a year. One Dane out of four is a nonreader. In Britain, the figure is 29 percent.

The Danes average 5.7 books a year. Britain, with 5.5 books a year, is next and Sweden, with 5.2, is in third place. The Dutch, who read 5.1 books a year, come next. The French and Swiss are also reasonably avid readers, with just under five books a year.

Italians are at the bottom of the ladder -- they read less than two books a year. The Austrians (2.6) and Spanish (2.8) are just above.

Figures are not available for the number of books Americans read, but we certainly buy them. On average we spend around $20 a year on books -- more than twice as much as is spent in any country except Switzerland and Sweden. In Switzerland the figure is nearly $14, in Sweden about $13.50. The British spend less than half as much on books as the average American.