Subtract till 100

Calculate:

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

48	-	31	=
95	-	23	=
73	-	44	=
89	-	44	=
50	-	31	=
40	-	30	=
86	-	3	=
95	-	7	=
71	-	49	=
97	-	36	=