Subtract till 400

Calculate:

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

348	-	168	=
240	-	97	=
84	-	44	=
372	-	182	=
209	-	75	=
166	-	101	=
315	-	73	=
248	-	129	=
186	-	160	=
314	-	143	=