adding
33+36=
69
45-39=
6
48+56=
104
23+34=
57
23-12=
11
53+68=
121
78-46=
32
78-56=
22
45+67=
112
64+78=
142
98+87=
185
112-78=
34
234+456=
690
345+56=
401
132+123=
255
167+137=
211
345-267=
78
456+678=
1134
456+870=
1326
678-567=
111
1536+3456=
4992
678-456=
222
890-785=
105
1233+1233=
2466
2222+3333=
5455