Number Pyramids
Age 11 to 14
Challenge Level
Try entering different sets of numbers in the number pyramids. How does the total at the top change?
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?
Crossed Ends
Age 11 to 14
Challenge Level
Crosses can be drawn on number grids of various sizes. What do you notice when you add opposite ends?
Perimeter Expressions
Age 11 to 14
Challenge Level
Create some shapes by combining two or more rectangles. What can you say about the areas and perimeters of the shapes you can make?
Special Numbers
Age 11 to 14
Challenge Level
My two digit number is special because adding the sum of its digits to the product of its digits gives me my original number. What could my number be?
Quadratic Patterns
Age 11 to 14
Challenge Level
Surprising numerical patterns can be explained using algebra and diagrams...
More Number Pyramids
Age 11 to 14
Challenge Level
When number pyramids have a sequence on the bottom layer, some interesting patterns emerge...
Reversals
Age 11 to 14
Challenge Level
Where should you start, if you want to finish back where you started?
Fibonacci Surprises
Age 11 to 14
Challenge Level
Play around with the Fibonacci sequence and discover some surprising results!
Always a Multiple?
Age 11 to 14
Challenge Level
Think of a two digit number, reverse the digits, and add the numbers together. Something special happens...
Think of Two Numbers
Age 11 to 14
Challenge Level
Think of two whole numbers under 10, and follow the steps. I can work out both your numbers very quickly. How?
Creating and Manipulating Linear and Quadratic Expressions - Short Problems
Age 11 to 16
A collection of short problems on creating algebraic expressions.
The Number Jumbler
Age 7 to 14
Challenge Level
The Number Jumbler can always work out your chosen symbol. Can you work out how?
You may also be interested in this collection of activities from the STEM Learning website, that complement the NRICH activities above.
NRICH is part of the family of activities in the Millennium Mathematics Project.