Unit 4: Subtraction Within 10: Friendly Notes (pp. 27-28) Unit 4: Subtraction Within 10: Exercise 1B: Making Subtraction Stories (p. 33) Unit 4: Subtraction Within 10: Exercise 2B: Methods of Subtraction (p. 40) Unit 4: Subtraction Within 10: Exercise 2C: Methods of Subtraction (p. 42)