Find out what they need to learn as a next step and teach it. Simple. You mention 'provide' for them. Don't fall into the trap (as I did in my early career) that you are there to simply provide a task for the children. They need to be taught the skills. As with the Maths thread, if that means it needs to be done in a guided group because the rest of the class have secured it, then that is the way forward.