When completing calculations in maths, I've sometimes found that a child has gone through a whole lesson and some how managed to get all or most of the work wrong and not been picked up by a peer or an adult. While on one level this is not a huge problem, as it can be followed up later, it's not ideal.
I'd been looking for a way to avoid this and here's what I came up with...
Give the children the answers.
A) Get the children to start and after a few minutes show the answers to question one for all levels of differentiation, a few minutes after that the next ones and so on...
B) Get the children to start and then put the the answers to the first three questions only, as a guide. Children complete the rest of the work without know the answers.
C) Give the children the questions, with the answers already filled in.
By no means do I use this all the time. It's a idea, to use now and again. Does it work? Yes. The children need to understand that maths (or any work) is not always about getting the right answer. Mistakes are ok. In a lesson, children are learning, trying out and developing methods. Not doing a 'getting ten right answers' exercise. Children need to be confident in trying out their methods or jottings, comparing their answer to the one given and then, if there are any errors, they need to look for what went wrong, seek help from a peer or talk to an adult.
Give it go. Not every lesson though.