Manipulatives can be used to help show  fair shares. 

A whole shows an object as 1 piece.  The following objects show whole pieces.

We can pretend we are sharing the whole piece with one other person.

Each person would now get one of the two equal pieces.

I always think of when I was little and had to share with my sister. 

We used "One for me and one for you."  The colored pieces below show what my

sister would get.  The white pieces show my fair share.