
Special numbers
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?

Number pyramids
Try entering different sets of numbers in the number pyramids. How does the total at the top change?

More number pyramids
When number pyramids have a sequence on the bottom layer, some interesting patterns emerge...

Your number is...
Think of a number and follow the machine's instructions... I know what your number is! Can you explain how I know?

Harmonic triangle
Can you see how to build a harmonic triangle? Can you work out the next two rows?

Crossed ends
Crosses can be drawn on number grids of various sizes. What do you notice when you add opposite ends?

Always a multiple?
Think of a two digit number, reverse the digits, and add the numbers together. Something special happens...

Perimeter expressions
Create some shapes by combining two or more rectangles. What can you say about the areas and perimeters of the shapes you can make?



Fibonacci surprises
Play around with the Fibonacci sequence and discover some surprising results!

Puzzling place value
Can you explain what is going on in these puzzling number tricks?
