GXQ
     +--------
HXHX | HFLPUTN
      -HNFNN
       =====
        PGTXT
       -PLXLP
        =====
         NQTFN
        -TFHFP
         =====
          HHGX

base: 10
letters: FGHLNPQTUX
difficulty: intermediate
restrictions: no multiplication