[pstricks] Shaded boxes request for ideas

[David Arnold]

All, I'd like to do the following:

\begin{tabular}{ccccc}
4 & more than & number & is & 12\\
4 & $+$ & $x$ & $=$ & 12
\end{tabular}

However, on the first line I'd like to put the 4, number, and 12 is  
boxes of equal size, no boundary, but background shading in cyan. On  
the first line, I'd like the + and the = to centered vertically in  
relation to the boxes around the 4, number, and 12.

Later, I'd like to expand this idea to a first row containing

Original\\Balance & plus & Mandy's\\Deposit & is & New\\Balance

The \\ means to imply that "Original Balance" is typeset as two lines  
in one shaded background box, again vertically centered on the "plus."

Possible with PSTricks?

Looking for ideas.

Thanks

David