Subtract till 400

Calculate:

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

385	-	156	=
303	-	97	=
208	-	175	=
335	-	53	=
281	-	15	=
358	-	85	=
266	-	115	=
315	-	73	=
399	-	40	=
88	-	23	=