Subtract till 400

Calculate:

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

161	-	116	=
183	-	164	=
378	-	41	=
129	-	38	=
30	-	16	=
319	-	10	=
193	-	128	=
330	-	150	=
328	-	74	=
230	-	172	=