A worksheet with a set of 8 column subtraction calculations, each with a different deliberate mistake (all except number 5, which is correct).
I searched the internet for something like this and couldn't find one. So I had to make it.
It's a PDF, I'm afraid, since it was easier for me to write them out by hand than work out how to do it on a computer.
Also I didn't do an answer sheet. But then you're maths teachers, so I'm sure you'll manage to work them out !