question: How many more households had a female householder with no husband present compared to a  male householder with no wife present?
#1 return households 
#2 return #1 that had a female householder  with no husband present 
#3 return #1 that had a male householder  with no wife present 
#4 return number of  #2 
#5 return number of  #3 
#6 return difference of #4 and  #5