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?

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

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

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

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

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

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

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

Where should you start, if you want to finish back where you started?

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

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

A collection of short Stage 3 and 4 problems on creating algebraic expressions.