The masters text box are only for changing style eg. red size 11

Don't use the 'side masters' text box to replicate a word onto every slide. Delete the masters text box and replace it with one of your own.

Remove the bottom three boxes on each side or ignore them as 'slide master' ignores them completley, add a new text box and put the function into it.Don't add the page numbers manually.

Remember main areas of the 'slide master' and just text and colour,everything else is just a guide-you must use your own textbox in an exam