Adding till 400

Calculate:

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

172	+	176	=
79	+	59	=
26	+	43	=
199	+	106	=
54	+	87	=
55	+	74	=
155	+	189	=
34	+	53	=
68	+	85	=
39	+	50	=