# What went wrong? TES Maths Resource of the Week

To see all of the work I do for TES Maths, including Resource of the Week, Inspect the Spec, Pedagogy Place, Maths Newsletters and Topic Collections, please visit the TES Maths Blog here

What is it?
I have always been a believer that a sound knowledge of possible students misconceptions is one of the keys to successfully planning and teaching a given topic. When we are aware of potential misconceptions, we can plan for them – arming ourselves with explanations and supporting resources – as opposed to being caught out in the heat of the moment by unexpected errors that we must attempt to diagnose and resolve with 30 expectant faces staring up as us. That is one way this exceptional resource can help. It is a collection of 90 common Key Stage 2 students errors, presented in the format of What Went Wrong? There are some absolute classics here, such as:
Rebecca simplifies 4/9 to 2/4.5. What went wrong?
Alexia is working out the area of a triangle. She adds the base and height and then multiplies by two. What went wrong?
Mohamed is multiplying 10.1 by 100. He says the answer is 10.100. What went wrong?
And although this resource has been designed with Key Stage 2 students in mind, I know it will be of great use with my Key Stage 3, and even Key Stage 4, classes.

How can it be used?
I can see two main uses for this wonderful resource. The first is as a planning tool. It is an excellent way to inform teachers of all experiences – but in particular those who have not been teaching for long – of where students are likely to go wrong. This enables us to plan for these errors. But it can also be used in lessons. Once students have been taught the correct way to do something, and practiced this method, they can then be presented with a selection of misconceptions and challenged to explain what went wrong. This could lead to some fascinating, fruitful discussions, as well as helping students develop the ability to articulate and argue their thoughts about mathematics. But one word of caution – I would be careful to ensure that students have experienced the right way of doing something plenty of times first, otherwise they may be just as likely to remember and reproduce what went wrong as what went right!

Thanks so much for sharing
Craig Barton