I invented the 3 box method after teaching for many years and becoming frustrated when pupils still had difficulties doing reverse percentages. It is a self-explanatory power point for teachers to use in the classroom and to help students revise. I start in Year 8, revise in Year 9 and then it’s the easiest topic for me to revise at IGCSE or GCSE! The two methods are useful for doing with and without calculators and they are appropriate for all levels of students. The multiplier method also leads nicely into compound interest problems. The ratio method is excellent for students whose English is of a low level as it makes them read the question carefully. Students love using the 3 box method!