On the farm, there are $$5$$ sheep, $$5$$ hens, $$2$$ dogs, $$2$$ cats, and the farmer. How many legs are there altogether? (2006 Math Kangaroo Problem, Level 1-2, Question \#15) 
Overseas Competition->Knowledge Point->Word Problem Modules->Unitary Method Problems->Finding the Unit Rate and then the Total Value
$5\times4+5\times2+2\times4+2\times4+2=48$ 