## 22 May 2016

### #mathscpdchat - Celebrating Don Steward

Please join me for #mathscpdchat at 7pm on Tuesday 24th May to explore Don Steward's fantastic resources.

Don's blog Median has recently passed its millionth view so this seems like a good time to share our favourites from his vast collection of rich tasks. Join the chat to discuss which resources you've tried and which have worked well.

To start us off, here are three of my favourites.

1. 'One incorrect simplification'

I love this set of tasks. When I took over my current Year 11 class in October, I gave them this activity in the first lesson. At the time they were working at GCSE grade B or C and it was important for me to know how fluent they were with algebra. This activity is really engaging - as my students got stuck in, I had the opportunity to circulate, assess their understanding and discuss common misconceptions. They found the task accessible but quite challenging, which set the tone for what their maths lessons with me would be like.

This expression caught most of them out:
I'm sure you can see what the common mistake is here - most students incorrectly simplified this to 3 + 5n. This raises a useful discussion about grouping and brackets, or lack of brackets.

This activity also works brilliantly as a warm-up on A level induction day.

2. Difference of Two Squares
Recognising and being able to factorise a difference of two squares is a useful skill throughout GCSE and A level.

Give a student an algebraic fraction to simplify and you'll often find that they have no idea what to do with a 4x2 - 9 in the numerator, even though they seemed to understand how to factorise a difference of two squares when you previously taught it.

Don Steward has some great activities for teaching this topic, culminating in this awesome set of challenging questions. I love these.
This reminds me of another Don Steward task - 'Mega hard powers questions' which offers stretch and challenge for students learning fractional and negative indices. This task works well at A level too.

I like it that both of these tasks help students realise how much easier it is to use improper fractions rather than mixed numbers or decimals.

3. Form and Solve a Quadratic
Forming equations comes up a lot in GCSE exams (particularly in Linked Pair GCSE, which is what I've been teaching this year). I'm not sure our students get enough practice of this - which is partly why so many were stumped by Hannah's Sweets last year. Don Steward has a lovely set of tasks for forming and solving quadratics.

Students often find it really hard to know where to start on problems like this so careful questioning and scaffolding may be needed.

In this post I've only shared algebra resources, but bear in mind that Don's resources are awesome for shape, measure, number, proportional reasoning, data and probability too. I will share many more resources during the chat on Tuesday. See you then.