These squares have been made from Cuisenaire rods. Can you describe
the pattern? What would the next square look like?
Cut differently-sized square corners from a square piece of paper
to make boxes without lids. Do they all have the same volume?
Can you use this information to work out Charlie's house number?
Think of a number.
Subtract your starting number.
Is the number you're left with odd or even?
Try with other numbers.
What do you notice?
How do these images help you explain your observations?