Colin Foster's Mathematics Education Blog

Zero is a strange number - learners sometimes even doubt if it is a number...  In my articles in Mathematics in School , I often address ...

If 'proportional' or 'multiplicative' thinking/reasoning is the central idea in age 11-14 mathematics, then how might we do...

Not all commonly-used representations of number are necessarily equally helpful. We shouldn't just assume that anything 'visual'...

How accurately do things need to be  drawn  to evidence conceptual understanding? When are accurate drawings helpful and when are they unnec...

Can a factor be a fraction? People sometimes agonise over whether a fraction such as $\frac{2}{3}$ can be called ‘a factor’ of another numbe...

I have a tendency to assume that concepts get more difficult as the number of dimensions increases. Length is pretty straightforward, surely...

Sometimes a superficially small tweak to a task - changing just one little thing - can dramatically alter it, and mean that a lot more think...

People often say or imply that when teaching mathematics 'open questions' are simply better than 'closed questions'. Instead...

Do you have tasks that you use in lessons that "can't fail"? Favourite tasks that you've used many times and that always s...