First of all I calculated how many squares there were of each colour.
Working out how many squares there were in the top part was the hardest as I had to make sure that I didn't overlap the squares.
In total there were:
Outer sides: 128 squares
Bottom: 64 squares
Top: 192 squares.
Within the top section, the colours were as follows:
Orange: 40
Green: 40
Purple: 64
I reduced the scale factor, and divided everything by 4. That way I could make a reasonably sized model. I drew it onto squared paper, then recreated it to make sure everything fit. I did this so that I could visualise it, as if I were really wrapping the auditorium.
Matthew from Dulwich College Suzhou in China sent in this picture:
Saksham from Hounslow Town Primary School sent in this picture:
Thank you for these good solutions that probably tested your visualising skills.