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?
What's in a Name?
Age 5 to 7 Challenge Level:
What do you notice about these squares of numbers? What is the same? What is different?
Digit Addition
Age 5 to 11 Challenge Level:
Try out this number trick. What happens with different starting numbers? What do you notice?
Surprising Split
Age 7 to 11 Challenge Level:
Does this 'trick' for calculating multiples of 11 always work? Why or why not?
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?
The Number Jumbler
Age 7 to 14 Challenge Level:
The Number Jumbler can always work out your chosen symbol. Can you work out how?
Your Number Is...
Age 7 to 14 Challenge Level:
Think of a number and follow the machine's instructions... I know what your number is! Can you explain how I know?
Neighbourly Addition
Age 7 to 14 Challenge Level:
I added together some of my neighbours house numbers. Can you explain the patterns I noticed?
NRICH is part of the family of activities in the Millennium Mathematics Project.