16 A series of books, written articles, handouts and worksheets in the field of arithmetic, mathematics, primary and secondary education; Books in the field of arithmetic, mathematics, primary and secondary education; Children's activity books; Children's books; Children's interactive educational books; Educational books featuring arithmetic problems, math problems, teacher's guides and teacher's manuals; Educational publications, namely, books, workbooks, work sheets, textbooks, booklets, teacher's manuals, teacher's guides, in the fields of arithmetic, mathematics, primary and secondary education; Manuals in the field of education and teaching of arithmetic, mathematics, primary and secondary education; Publications, namely, books, booklets, textbooks, workbooks, work sheets, teacher's manuals, teacher's guides in the fields of arithmetic, mathematics, primary and secondary education; Textbooks in the field of arithmetic, mathematics, primary and secondary education; Workbooks directed to arithmetic, mathematics, primary and secondary education