Stage: 2 Challenge Level:
Can you picture how many cubes are in each layer of the six-layered
pyramid with 91 cubes in total?
Which layers will have a cube which is directly below cube 1?
Which layers will have a cube which is directly below cube 4? And
You might find it useful to record the layers somehow.
Try comparing the positions of the cubes in the first and second
pyramids. What do you notice?