Rose filled up $$4$$ pails with $$4$$\textbf{~}ℓ of water each. After filling up the $$4$$ pails, Rose still had $$7$$ ℓ of water left. What was the original volume of water Rose had at first?  The original volume of water Rose had at first is~\uline{~~~~~~~~~~}~ℓ\textbf{.~} 
Overseas Competition->Knowledge Point->Word Problem Modules->Unitary Method Problems->Finding the Total Value using Unitary Method