This excellent suite of printable activities by teachingimage.com provides a wide variety of subtraction based activities to accommodate most requirements.
Beginning with simple numbers, it moves through a series of progressively more complicated subtraction processes involving combinations of two and three digit numbers.
There is also a series of exercises to enable practice of subtracting through a tens barrier before moving on to exercises on column subtraction and culminating in gap fill activities, requiring pupils to reverse engineer subtraction sums.
Each at the sheets comes with answers. There are 21 separate printable activities in total.