Subtract till 400

Calculate:

Number of examples:
Numerical difficulty:
Range of values:
Multiplicity:

205	-	117	=
289	-	177	=
375	-	189	=
48	-	28	=
226	-	169	=
318	-	23	=
52	-	28	=
230	-	7	=
377	-	145	=
389	-	79	=