Pupils earn points by solving the equations. Easier questions earn less points so pupils self-differentiate and decide their own level of difficulty for themselves (although the teacher should check that they do this sensibly of course!).
I tell pupils that those with most points after a given time period win. The competitive nature of this activity encourages pupils to push themselves more than they would usually and I’m always pleasantly surprised at what equations they can do here.
Answers to the equations are included. as well as an easier version (v3) with no negative answers.
Tried and tested in the classroom many times. This download includes a files as well as the original word files for easy editing.