Adding till 400

Calculate:

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

220	+	149	=
15	+	19	=
141	+	217	=
159	+	213	=
209	+	114	=
68	+	52	=
26	+	20	=
12	+	13	=
56	+	42	=
207	+	157	=