Adding till 400

Calculate:

Number of examples:
Numerical difficulty:
Range of values:
Multiplicity:

72	+	80	=
94	+	144	=
51	+	52	=
2	+	3	=
112	+	57	=
268	+	131	=
84	+	136	=
181	+	153	=
28	+	41	=
33	+	37	=