Adding till 100

Calculate:

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

48	+	51	=
15	+	20	=
18	+	26	=
17	+	11	=
67	+	30	=
27	+	21	=
11	+	7	=
15	+	37	=
46	+	51	=
13	+	10	=