1.   Find the number that completes the number sentence. Then identify the property or rule.

12 − ∅ = 12
    A. 43; Identity Property of Addition
    B. 0; Associative Property of Addition
    C. 0; Commutative Property of Addition
    D. 0; Subtraction Rule
    Hint
  2.   Find the number that completes the number sentence. Then identify the property or rule.

24 + ∅ = 18 + 24
    A. 18; Commutative Property of Addition
    B. 18; Associative Property of Addition
    C. 0; Identity Property of Addition
    D. 6; Subtraction Rule
    Hint
  3.   Find the number that completes the number sentence. Then identify the property or rule.

43 + ∅ = 43
    A. 12; Subtraction Rule
    B. 0; Identity Property of Addition
    C. 0; Commutative Property of Addition
    D. 0; Associative Property of Addition
    Hint
  4.   Add mentally.

32 + 18 + 40
    A. 70 B. 80
    C. 100 D. 90
    Hint
  5.   Add mentally.

51 + 22 + 9
    A. 81 B. 72
    C. 82 D. 92
    Hint