Adding till 100

Calculate:

The number of examples:
Numerical difficulty:
Range of values:
Multiplicity:

2	+	2	=
11	+	8	=
20	+	29	=
34	+	48	=
31	+	69	=
38	+	55	=
18	+	23	=
14	+	9	=
26	+	26	=
25	+	23	=