Adding till 100

Calculate:

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

33	+	42	=
21	+	22	=
7	+	7	=
34	+	27	=
34	+	63	=
2	+	2	=
39	+	31	=
16	+	10	=
36	+	46	=
16	+	22	=