Children can become more intelligent by practicing a study routine and reviewing the lessons that they had that day religiously finishing, homework activities and reading about the next lessons in advance off.
Another way, is to become an extensive reader.
The vast knowledge that they can gain from books or any.
Other reading material will help them flesh out their own opinions.
And ideas about any issue with lastly traveling and experiencing different cultures and situations first-hand will give them a wider and more objective view of the world.