Without regrouping
99-34=
65
92-18
74
56-39=
17
43-12=
31
78-25=
53
44-23=
21
86-17=
69
45-26=
19
43-25=
18
20-15=
5
67-35=
32
44-39=
5
71-45=
26
52-19
43
45-26=
19
84-83=
1
51-32=
19
43-17=
26
87-46=
41
70-37=
89-48=
41
60-27=
42
90-65=
25
50-32=
18
55-24=
31