I am running kpdf 0.5.7 (using kde 3.5.7). If I want to zoom the page, all
I seem to have is Menu>View>Zoom In, Zoom Out. But what if I want to zoom
exactly to a given degree of magnification. I do not know how to do it
and I have read the manual all through.

However, if I associate pdf files with kpdf, then I am presented with
a box where I can set the magnification exactly as I want. For instance,
153%. But then, the look of the window where pdf opens is quite different.
For instance, I have no menu bar, only icons. There must be a way of
specifying the degree of magnification. If anyone could give a hint
I would be obliged. Thanks for your time.

Enrique.

Try using Ctrl & m to display your menu bar. Then go to Settings--> Configure toolbars and see if you can add the zoom percentage box.

Thank you very much for your suggestion, Nexus.
I tried it and it worked.