Each issue, v. 3- Feb. 6, 1958 -, accompanied by a teacher's issue called: Feb. 6, 1958-May 12, 1965, Science teacher's world; Sept. 16, 1965-May 18, 1970, Scholastic teacher - science edition (subtitle varies); Sept. 14, 1970- , Teacher's edition of Science world. and This set comprises edition 2.
Divided in Feb. 1961 into two editions: edition 1, for 7th, 8th and 9th grade students; and edition 2, for 10th, 11th and 12th grade students. and Volume numbering changed in Sept. 1968; vols. 17-23 repeated.
Merged in Sept. 1968 with the former Science world - edition 1.