Complex sentence: That year 60 children were tested and 20 selected with scores over 140-160--courses were offered in computers, mathematics, astronomy, television and chess to these 60 children, with higher level courses for the 20 highly gifted.
Split into simpler sentences: That year 60 children were tested and 20 selected with scores over 140--160. Courses were offered in computers, mathematics, astronomy, television and chess to these 60 children, with higher level courses for the 20 highly gifted.