17 + 3 =

(a)  

25 + 5 =

(a)  

61 + 9 =

(a)  

75 + 5 =

(a)  

59 + 1 =

(a)  

24 + 6 =

(a)  

32 + 8 =

(a)  

15 + (a)   = 20

31 + (a)   = 40

54 + (a)   = 60

Write only one digit.

(a)   6 + 4 = 50

Write only one digit.

6 (a)   + 3 = 70

42 + 8 =

(a)  

31 + (a)   = 40