Adding till 400

Calculate:

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

1	+	3	=
178	+	165	=
173	+	145	=
8	+	7	=
55	+	165	=
94	+	90	=
132	+	141	=
218	+	164	=
99	+	65	=
131	+	199	=