problem
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?
problem
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?
problem
More number pyramids
Age
11 to 14
Challenge level
When number pyramids have a sequence on the bottom layer, some interesting patterns emerge...
problem
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?
problem
Harmonic triangle
Age
14 to 16
Challenge level
Can you see how to build a harmonic triangle? Can you work out the next two rows?
problem
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?
problem
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...
problem
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?
problem
Beach huts
Age
11 to 14
Challenge level
Can you figure out how sequences of beach huts are generated?
problem
Reversals
Age
11 to 14
Challenge level
Where should you start, if you want to finish back where you started?
problem
Fibonacci surprises
Age
11 to 14
Challenge level
Play around with the Fibonacci sequence and discover some surprising results!
problem
Puzzling place value
Age
14 to 16
Challenge level
Can you explain what is going on in these puzzling number tricks?
list
Creating and manipulating linear and quadratic expressions - short problems
A collection of short problems on creating algebraic expressions.