>>698
(5.625)10=(2^2+2^0+2^(-1)+2^(-3))10=(101.101)2

(1000 1001 1010 1011)2 = (89AB)16

101.1
+11.11
-------
1001.01

101.1
*10.11
------
  1011
  1011
1011
-------
1111.001