The Second Grade Standards Edition Unit 1 extends previous learning to an understanding of addition and subtraction within 50. regrouping is introduced in addition and subtraction separately, using manipulatives, place value charts, visual cues, and TouchPoints. Skills are used in making comparisons, finding the values of unknowns, and solving one- and two-step problems. Multiple instructional supports include step-by-step instruction, visual cues, meaningful repetition, and clearly defined strategies.