Adding till 400

Calculate:

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

127	+	68	=
47	+	33	=
128	+	206	=
72	+	109	=
181	+	109	=
58	+	73	=
5	+	15	=
147	+	113	=
4	+	5	=
28	+	39	=