Adding till 100

Calculate:

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

41	+	57	=
20	+	25	=
4	+	7	=
9	+	18	=
53	+	33	=
11	+	13	=
4	+	3	=
23	+	44	=
39	+	37	=
6	+	3	=