Adding till 400

Calculate:

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

144	+	118	=
75	+	118	=
129	+	90	=
123	+	118	=
199	+	85	=
28	+	28	=
35	+	44	=
198	+	123	=
143	+	130	=
5	+	6	=