Add 13 5/12 +(-4 11/12) . reduce, if possible

   Arranging these addends vertically may make the work easier:

    13 5/12
   -4 11/12)


Since 11/12 is larger than 5/12, we must borrow from 13:

12 + 12/12 + 5/12
 -4        -11/12
  
8         17/12-11/12        =    8 6/12   = 8 1/2   = 8.5 (answers)

11/2.2 = 5 inches for the length 8.5/2.2= 3.86 inches for the width