Got it

All the possible answers are multiples of 9 and on the square on the second phase all the multiples of nine have the same answer.

10	1	0	9
11	1	1	9
12	1	2	9
13	1	3	9
14	1	4	9
15	1	5	9
16	1	6	9
17	1	7	9
18	1	8	9
19	1	9	9
20	2	0	18
21	2	1	18
22	2	2	18
23	2	3	18
24	2	4	18
25	2	5	18
26	2	6	18
27	2	7	18
28	2	8	18
29	2	9	18
30	3	0	27
31	3	1	27
32	3	2	27
33	3	3	27
34	3	4	27
35	3	5	27
36	3	6	27
37	3	7	27
38	3	8	27
39	3	9	27
40	4	0	36
41	4	1	36
42	4	2	36
43	4	3	36
44	4	4	36
45	4	5	36
46	4	6	36
47	4	7	36
48	4	8	36
49	4	9	36
50	5	0	45
51	5	1	45
52	5	2	45
53	5	3	45
54	5	4	45
55	5	5	45
56	5	6	45
57	5	7	45
58	5	8	45
59	5	9	45
60	6	0	54
61	6	1	54
62	6	2	54
63	6	3	54
64	6	4	54
65	6	5	54
66	6	6	54
67	6	7	54
68	6	8	54
69	6	9	54
70	7	0	63
71	7	1	63
72	7	2	63
73	7	3	63
74	7	4	63
75	7	5	63
76	7	6	63
77	7	7	63
78	7	8	63
79	7	9	63
80	8	0	72
81	8	1	72
82	8	2	72
83	8	3	72
84	8	4	72
85	8	5	72
86	8	6	72
87	8	7	72
88	8	8	72
89	8	9	72
90	9	0	81
91	9	1	81
92	9	2	81
93	9	3	81
94	9	4	81
95	9	5	81
96	9	6	81
97	9	7	81
98	9	8	81
99	9	9	81