Subtract till 100

Calculate:

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

68	-	14	=
60	-	29	=
13	-	5	=
67	-	25	=
24	-	12	=
100	-	33	=
96	-	43	=
54	-	21	=
93	-	30	=
47	-	31	=