Completed this activity with my Year 6 class but suitable for most year groups. Takes a short amount of explanation but then children can complete in groups or independently. Puts the onus on the children to think of their own word/arithmetic problems and checks their own understanding.
Quite a simple task to run: children are presented with a room template with three doors containing a different answer on the front; they create a question card from one of their topics thus far and a correct answer for the question which aligns with one of the doors. These can then be compiled into a class set which can be preserved and used as you see fit, such as during wet breaks, golden time, a challenge during a lesson. This can added to as the year goes on and a way of revisiting topics.
Files contain: room template, question card template, explanation of activity (editable).