Adding till 400

Calculate:

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

117	+	138	=
133	+	226	=
159	+	159	=
103	+	85	=
4	+	1	=
9	+	9	=
184	+	167	=
23	+	26	=
166	+	131	=
38	+	15	=