A great activity for practising algebra skills – students collect like terms in order to answer questions and gradually reveal an image from a film.
First, print off all the questions and get the students to answer as many as they can in their books. Then, as a class, have the students volunteer their answers. If a student volunteers the correct answer, click the relevant box to make it disappear and reveal part of the film still.
(You might want to ask students to wait until all is revealed before actually identifying the film, so as not to spoil things for everyone else.)