(1) As can be seen from the fan-shaped statistical chart, marketing books are most popular with readers; People who buy popular science books are the least;

(2) 1÷2%=50 (ten thousand copies)

A: If the sales volume of popular science books last year was 1 10,000 copies, then * * * sold 500,000 copies last year;

(3)2 1%≈ 15

A: The sales volume of counseling books accounts for about15 of the total sales volume;

So the answer is: Fan, marketing, popular science, 50, counseling materials.