Adding till 400

Calculate:

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

23	+	14	=
86	+	66	=
69	+	145	=
121	+	106	=
62	+	63	=
35	+	53	=
33	+	31	=
31	+	18	=
118	+	191	=
67	+	127	=