Maths: The Cost of Building

For Maths today we were learning some geometry language like 'cube' and 'face'.  The context we were looking at this through was buildings.

We had several tasks to complete in our groups, including working out the cost of building materials and paint.

Check out some of the tasks below and see if you can solve the problems:

Each cube that is on the ground (1st story floor) costs $10
2nd story cube - $15
3rd story cube - $20
4th story cube - $25

What would these buildings cost?

What would the most expensive building cost?

How did you solve these problems?