1.   Find the missing number in the equation.

18 + 8 = 8 + __

    A. 10 B. 12
    C. 18 D. 8
    Hint

  2.   Find the missing number in the equation.

__ + 10 = 10 + 15

    A. 15 B. 10
    C. 25 D. 5
    Hint

  3.   Find the missing number in the equation.

14 + __ = 8 + 14

    A. 6 B. 14
    C. 22 D. 8
    Hint

  4.   Find the missing number in the equation.

13 + 12 = 5 + 8 + __

    A. 10 B. 13
    C. 12 D. 4
    Hint

  5.   Find the missing number in the equation.

8 + 5 + 7 = 8 + 7 + __

    A. 5 B. 15
    C. 6 D. 7
    Hint