This is an SMSG elementary school text for second-grade students. The development of mathematical ideas in the text is grounded in appropriate experiences with things from the physical world and the immediate environment. Chapter topics include: (1) sets and numbers; (2) addition and subtraction; (3) sets of points; (4) linear measurement; (5) computing sums and differences; (6) congruence of angles and triangles; (7) arrays and multiplication; and (8) division and rational numbers. (MP)