problem Terminating or not Age 11 to 14 Challenge level Is there a quick way to work out whether a fraction terminates or recurs when you write it as a decimal?
problem Neighbourly Addition Age 7 to 14 Challenge level I added together some of my neighbours' house numbers. Can you explain the patterns I noticed?
problem Truth or Lie Age 7 to 11 Challenge level Take a look at the video of this trick. Can you perform it yourself? Why is this maths and not magic?
problem Surprising Split Age 7 to 11 Challenge level Does this 'trick' for calculating multiples of 11 always work? Why or why not?
problem Digit Addition Age 5 to 11 Challenge level Try out this number trick. What happens with different starting numbers? What do you notice?
problem Unexpected Ordering Age 5 to 7 Challenge level Watch the video of Fran re-ordering these number cards. What do you notice? Try it for yourself. What happens?
problem Window frames Age 5 to 14 Challenge level This task encourages you to investigate the number of edging pieces and panes in different sized windows.
problem Bundles of Cubes Age 7 to 11 Challenge level Watch this animation. What do you notice? What happens when you try more or fewer cubes in a bundle?
article Mastering Mathematics: The Challenge of Generalising and Proof This article for primary teachers discusses how we can help learners generalise and prove, using NRICH tasks as examples.
problem Maxagon Age 11 to 14 Challenge level What's the greatest number of sides a polygon on a dotty grid could have?