Where should the numbers go?

In K3G we're not sure about something. Maybe you can help?

We started with all the numbers from zero to ten at the bottom of the board. Then one by one we moved them up to the line.

O and 1 and 2 were moved up to the left:

 Then we moved 9 and 10 to the right:

 More went to the left and right:

 Soon we were left with just 5 to put on:

Now we're really not sure where to put 5!

So, some thought 5 should go with the small numbers, some thought it should go with the big numbers, and some thought it should go in the middle!

What do you think?