Subtract till 100

Calculate:

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

35	-	2	=
83	-	40	=
79	-	20	=
57	-	35	=
32	-	26	=
75	-	7	=
83	-	43	=
47	-	33	=
81	-	48	=
65	-	8	=