css3 scale transform on parent div but keeping constant size in some of the associated divs

I'm using css3 scale transform to scale a div that contains other divs inside.

The problem I have is that some of the inner divs I need to keep as they were, basically as if they were not scaled, their size should not change, however I do need to scale the parent div with everything else inside.

How can you reverse the scaling in some of the divs?
I am trying to apply an inverse scaling.
If the overall div had applied a value of 1.5 , I'm trying to find what value I should now scale the other divs to revert them visually to how they looked before.