Boolify is a great tool to teach children (and adults too!) how to properly use a search engine.
Finding content using search is a very important skill to learn. One often finds millions of search results after entering a keyword. In order to quickly find the needed content, you should refine the search. Command line searches use the concept of boolean operators to achieve this goal. In simple terms, this means learning to use AND, OR, NOT in a search to refine the results. By combining them together, one can narrow down a search to give exactly what is needed...
Boolify Boolean Graphical Search Learning Tool