Adding till 400

Calculate:

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

189	+	207	=
83	+	158	=
111	+	87	=
37	+	53	=
65	+	58	=
158	+	213	=
61	+	99	=
141	+	84	=
115	+	91	=
133	+	145	=