My colleague Jane introduced me to ‘Tick or Trash’ worksheets and they are just brilliant!
The basic idea is you have a table with three columns. The middle column is the question, either side are the solutions of fictional pupils. I called mine Kirsty and Kyle as I don’t teach anyone with those names. One solution is correct, one isn’t. Your students must decide who is right and why. They must then decide where the other pupil went wrong.
The worksheet I’ve put together is about inequalities. It covers using a numberline, solving a linear inequality with the unknown on one/two sides and dealing with a negative. There is also a QR code linking to a short YouTube clip (not mine) on solving inequalities. Download it here. The basic colour coded answers are available too. Note: the files are in docx format.
This is an ideal activity to use with the Validator concept. I would give my peer Validator the answer sheet to refer to, but the explanations would be down to the students to gauge if they understood.