The United States' once-every-ten-years ''report card'' is now out in the form of preliminary findings from the 1980 census. The data suggest kudos for progress in a number of crucial social and economic areas, as well as some warnings about the future.
Americans cannot help but take satisfaction in the fact that so many of their fellow citizens are now completing high school and going on to college. For the first time more than half of all Americans in every state in the union age 25 and older--in fact, 66.3 percent of all Americans--have graduated from high school. Some census analysts say that such a milestone is as significant as, for example, the landmark finding of the 1920 census that for the first time more than half the US population was found in cities. Add the fact that 16.3 percent of all Americans have now completed four years of college (up from 11 percent in 1970), and it quickly becomes apparent that the US now has a better educated (although not necessarily wiser) population than perhaps at any time in its history.
There are other achievements: the fact that so many women and young people have been absorbed in the work force over the past decade; the mobility with which Americans have been able to relocate in new communities (mainly in the South and West), in contrast with, say, the situation at the turn of the century when most people seldom lived far from the place of their birth; or, yes, even the fact that central air conditioning is now found in more than a quarter of all households. Ecological purists may question the energy waste often found in air conditioning, but one suspects that the Founding Fathers who so frequently complained about the summer heat in colonial and revolutionary days would have eagerly welcomed a few minutes a day in front of a cool air duct.
The census findings also disclose some ''problem areas'' that will have to be addressed through public policy or individual effort in the years ahead. Among such issues:
* Housing. While Americans showed gains in building new housing units during the 1970s, there is now evidence that significant social and class distictions may be developing between homeowner and renter families and individuals. Obviously, the US must not give up its long-range historical objective of ensuring that every family or person who wishes to can eventually own a home.
* Transportation. More Americans are eschewing public transportation and driving themselves to work. Yet many of the nation's roadways and bridges are in desperate need of major repair work.
* Families. Slighly over one-fourth of all households comprise persons living alone or with nonrelatives. Is the nation as a whole--increasingly urbanized--ready to deal with the long-range needs of so many persons living outside the traditional family structure?
* Poverty. There are fewer ''poor people.'' But at the same time poverty, according to census director Bruce Chapman, ''seems to attach itself to people trying to raise children alone.'' Obviously society must give thought to this situation.