There are five kangaroo mothers, six kangaroo babies, and one kangaroo father. Each kangaroo mother should take care of the same number of kangaroo babies. How many kangaroo babies should kangaroo father take care of? (adapted from $$2011$$ Math kangaroo Problems, Level $$1-2$$, Question \#$$6$$) 
Overseas Competition->Knowledge Point->Word Problem Modules->Applying Addition and Subtraction->Including and Excluding 
The key point is that each kangaroo mother needs to take care of the same number of kangaroo babies. So $6$ (number of kangaroo baby) $$\div$$ $5$ (number of kangaroo mother)$=1\ldots\ldots1$, and the remaining one is taken care of by kangaroo father. 