This report is about working out the formula to a hidden faces equation, I will find the nth term, put my results into a table and, figure out if the formula works.

Method

I am going to find out how many hidden faces (the faces that aren’t visible from any angle) there on

1 cube

2 cubes

3 cubes

4 cubes

5 cubes

6 cubes

7 cubes

8 cubes

9 cubes

I am doing this to try and find an easier way to find out how many hidden faces there are in…. say 100 cubes rather than do trial and error, or put cubes together and work it out.

I will record my results in a table that has 3 columns,

1, number of cubes

2, number of hidden faces

3, the formula

I will prove this by picking a low number like..1, and a really high one like 100 and test my formula on it.

Hypothesis

I predict that the formula is 3n-2.

My formula works because

3n-2 = 3X1-2                31=3 3-2=1

it works with all numbers

3n-2 = 3X6-2

3X6=18                18-2=16