### Why do this
problem?

This problem demonstrates links between numbers and shapes. It
encourages children to visualise in the context of a number
sequence.

### Possible approach

To begin with, it would be good to let children talk about
what the next numbers in the sequence could be, without saying much
more. Share the class' ideas and invite children to explain how
they worked out their solution.

Give pairs of children objects which they could make into
pyramids, perhaps marbles with some blu-tak, and leave them to
explore.

In the plenary you could focus on any other sequences which
learners have investigated.

### Key questions

Can you make some sort of pyramid using these numbers of
marbles?

How would you make a different sort of pyramid? What is the
number sequence for that pyramid?

Can you make a different layered structure with the marbles?
What is the number sequence that goes with it?