How big a bubble can you blow?

With the dreary winter weather outside,

I thought it was time for something bright and cheery...

so bring on the gum-balls!

The only problem with this lesson is that 

there is no gum chewing at school.

The example above is mine.  

The students used 4 different brushes in this lesson

and how to shade circles to make them appear 3D.

I do believe I would like a piece of gum...