I’ve been looking at how to teach percentage increase and decrease at Key Stage 3. If you can find 20%, you can obviously increase by 20% by adding it on. But does this reinforce the misconception that percentages are an addition, rather than multiplicative, function? I’ve started teaching multipliers for increase and decrease to a wider range of pupils, so it makes sense to introduce the concept earlier. I’ve used finding 120% as a way to increase by 20%. It opens up discussion as to why this works and pupils can form their own ideas on how to decrease.

Image Credit: www.te

To reinforce and practice the idea of increase and decrease by percentages I’ve created some ‘Muppets’ themed Top Trumps cards (not licensed). You can download them here: Muppets Top Trumps (pdf)

There are only eight cards, but you could print out one set per pupil and shuffle them.