Adding till 400

Calculate:

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

157	+	190	=
61	+	58	=
37	+	33	=
162	+	172	=
170	+	188	=
91	+	163	=
88	+	103	=
170	+	171	=
28	+	82	=
138	+	68	=