15-610 3113 2930 19-7 8+4
18-917 4439 5885 11-711-4
11-=7 15-=4 +2=11
-9=5 -8=7 7+=16
11-=6 12-=8 14-=7
12->12-
+7<7+
17-9◯10-1 13-8◯15-9 7+4◯12-2
15-6◯3+5 12-5◯7+0 12-7◯15-6
14-( )=10
9+( )=12
15-( ) =6
3+( )=11
6+( )=12
9+( )=14
15-( )=10
8+( )=13
11-( )=4
6+ ( )=14
14-( )=5
7+( )=11
16-( )=14
18-( )=16
( )+15=18