Subtract till 400

Calculate:

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

170	-	130	=
197	-	25	=
265	-	52	=
246	-	111	=
266	-	140	=
393	-	11	=
296	-	95	=
39	-	33	=
213	-	93	=
224	-	191	=