I've just seen an online workshop from an art group I follow that your children in Year 8 might enjoy. Below is the link to the London Drawing Group website. From there click 'Menu' then 'events' and its the 'Matisse Drawing with Scissors' workshop. Its for all levels. It's on tomorrow, 6th May at 6.30pm. There is another Matisse workshop, Drawing with sticks too.
We recently learnt about the Artist, Matisse, and how in his later years he used scissors to draw with. The children were really engaged with it and the work they produced was ace so they may enjoy this.