Adding till 100

Calculate:

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

30	+	37	=
31	+	30	=
30	+	33	=
59	+	37	=
11	+	3	=
14	+	9	=
25	+	26	=
13	+	14	=
38	+	59	=
25	+	25	=