There are to be 6 homes built on a new development site. They could be semi-detached, detached or terraced houses. How many different combinations of these can you find?
Start with four numbers at the corners of a square and put the total of two corners in the middle of that side. Keep going... Can you estimate what the size of the last four numbers will be?
Find a great variety of ways of asking questions which make 8.
This is an easily presented problem that requires a bit of thinking as it's not necessarily obvious to pupils what needs to be done to obtain an answer. It demonstrates the power of trial and improvement, combined with a systematic approach and you could also use children's work to focus on different ways of representing a solution.