Adding till 400

Calculate:

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

35	+	30	=
230	+	96	=
116	+	163	=
28	+	16	=
43	+	42	=
46	+	61	=
28	+	31	=
12	+	13	=
151	+	155	=
23	+	34	=