Washington — The government's latest jobless figures only scratch the surface of a complex US employment situation, reflecting bright and darks spots. On the bright side, the economy continues to show an astonishing ability - when measured against the experience of other nations - to create new jobs.
Last month, for example, the overall unemployment rate in the US was 10.2 percent of the labor force, down only marginally from the 10.3 mark of March.
Yet the number of Americans at work increased by 355,000 to just under 99.5 million. President Reagan expressed bafflement that, given this job growth, the unemployment rate remained about the same.
The answer is that 300,000 more Americans were looking for work in April than had been the case the month before. Thus the increase in new jobs was only slightly larger than the growth of the labor force - the total number of people at work or searching for jobs.
This helps to explain why experts caution that the unemployment rate will decline very slowly this year, even if the economy continues to grow.
Throughout the United States, not counted on the official jobless rolls, are 1.8 million Americans who are called ''discouraged workers,'' people who have given up looking for jobs.
They are not included among the 11.3 million jobless Americans tallied by the US government in April. As the economy starts to grow, many discouraged people will register again for work, causing the Labor Department to list them as unemployed members of the work force.
Assuming all discouraged workers reentered the labor force, the economy would have to develop 1.8 million new jobs just to keep the unemployment rate from rising. This does not include jobs for each summer's batch of high school and college graduates.
Janet L. Norwood, commissioner of Labor Statistics, spoke in an interview of the ''dynamism'' of the US labor market. ''Over the decade of the 1970s, the US economy created 20 million jobs,'' said Dr. Norwood. This is a flexibility and growth unmatched by any other industrial power.
In 1970, according to Labor Department figures, 80.7 million Americans held jobs. In 1981, the number of people at work soared above 102 million. All this was accomplished during a period of economic turmoil, notably the oil price shocks of 1973-74 and 1979, double-digit inflation, and major recession.
Despite this resilience, the US has major structural problems to solve - one old, one new - before the employment picture brightens over all.
A long-standing problem is the inability of the US economy to absorb black Americans at the same pace it does whites. One in two black teen-agers is jobless. The overall black unemployment rate measured 20.8 percent in April, back up to a previous record.
These figures indicate that young blacks, once they enter their twenties, are more successful at finding jobs than they were as teen-agers. Nonetheless, a black jobless rate above 20 percent, says Dr. Norwood, is ''very serious'' for the nation as a whole.
A second structural problem is the increasing number of middle-aged, often highly skilled, men and women thrown out of work because their ''smokestack'' industries - including autos, steel, rubber, and textiles - are declining, at least in the number of people they employ.
This reflects a basic shift within the US economy away from manufacturing toward more jobs in service sectors - communications, tourism, health care, banking, and office work generally.
Within the manufacturing sector itself, a rapid transformation appears to be underway, with high-technology fields - requiring specialized skills - offering the best job opportunities for the future.
One result, according to Bob Greenstein, director of the Center on Budget and Policy Priorities in Washington, is that long-term unemployment has been increasing at a far more rapid rate than unemployment generally. The number of Americans who have been out of work for a substantial length of time, he says, has more than doubled since the beginnning of 1982.