The totality of rational expression addition and subtraction problems in Wentworth's New School Algebra (published in 1898) vs. the University of Chicago School Mathematics Project Algebra (published in 2002).
I. From Wentworth's New School Algebra, pp. 133, 134, 135, 137 [click to enlarge]:
II. From The University of Chicago Math Project Algebra, p. 335 336 341 343 [click to enlarge]