Adding till 100

Calculate:

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

49	+	41	=
11	+	11	=
27	+	23	=
28	+	42	=
36	+	37	=
50	+	47	=
7	+	8	=
14	+	15	=
38	+	40	=
35	+	38	=