Subtract till 400

Calculate:

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

296	-	161	=
311	-	188	=
392	-	172	=
308	-	191	=
214	-	122	=
252	-	98	=
192	-	43	=
141	-	60	=
343	-	133	=
146	-	97	=