42+(     )=50

(     )+38=46

(     )+21=34

(     )-29=5

42-(     )=27

(     )+4=21

44+(     )=44

(     )-13=19

(     )+2=50

(     )-1=40

22+(     )=46

37-(     )=7

47+(     )=49

45-(     )=25

(     )-31=2

33+(     )=48

(     )-21=8

2+(     )=30

(     )+5=50

15+(     )=21

(     )-17=12

(     )+6=31

(     )-34=4

30-(     )=0

44-(     )=6

(     )-35=1

38+(     )=50

(     )+16=28

(     )+16=24

48+(     )=50

49+(     )=50

29-(     )=25

(     )+36=39

(     )+12=45

15+(     )=27

0+(     )=25

21-(     )=6

(     )-9=40

38+(     )=48

(     )-31=6

27-(     )=25

24+(     )=36

22-(     )=3

(     )-29=4

(     )-0=22

47+(     )=50

(     )+1=45

(     )+4=21

(     )+5=39

(     )-15=9