Add the numbers outside to the number in the box. 
81
65 22
33 36
17
13
45
62 86
71
52 14
32 62
75
14
71
63 64
25
Add 32 to every number :
 
25 65 45 35 15 42 52 62
41 42 47 45 43 46 44 40
64 53 63 13 57 51 27 23
24 67 16 67 34 54 55 31
32 17 60 11 33 22 8 18

Add: 30, 21, 22, 31 to every number..

Add  units so thet you get tens.

Calculate:
15
26
37
48
59		 +
+
+
+
+		 7
8
5
5
3		 +
+
+
+
+		 9
7
9
8
9		 =
=
=
=
=		 .....
.....
.....
.....
.....
28
19
35
46
55		 +
+
+
+
+		 6
4
7
9
6		 -
-
-
-
-		 7
6
8
8
5		 =
=
=
=
=		 .....
.....
.....
.....
.....