16-(     )=4

20-(     )=9

17+(     )=20

(     )-4=10

(     )-9=8

(     )-10=4

(     )+5=11

17-(     )=6

(     )+0=13

13-(     )=8

13-(     )=6

(     )-6=6

(     )-7=4

(     )-19=1

(     )-1=13

(     )-9=3

4+(     )=19

(     )-0=17

13+(     )=17

2+(     )=11

1+(     )=20

(     )-4=15

(     )+12=16

(     )-3=12

(     )-4=13

17-(     )=16

8+(     )=11

(     )-5=13

(     )+9=15

13+(     )=16

12-(     )=5

(     )-14=3

12+(     )=13

(     )-15=3

17-(     )=10

12-(     )=6

(     )+2=11

(     )-5=6

(     )-11=4

8+(     )=17

20-(     )=10

(     )-6=9

(     )+13=14

11-(     )=11

0+(     )=15

2+(     )=19

3+(     )=18

18+(     )=20

(     )-4=7

14+(     )=16