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?
Add the sum of the squares of four numbers between $10$ and $20$ to the sum of the squares of three numbers less than $6$ to make the square of another, larger, number.