Math Worksheets for Kindergarten, 1st, 2nd, 3rd, 4th ... 2nd Grade Math Worksheets. Upon starting second grade, students should have mastered all of their addition facts, or fact families 1 to 10. If they have not mastered those facts, you should begin with the first-grade worksheets (Addition 1s through 9s / Fact Families 1 to 10 Add and Subtract) until they are ready to move forward.