Few days ago, someone show me a Youtube video on one method of calculation to ask me whether is it applicable for all cases.
I watched it.
After thinking, I do think that it's applicable for all cases.
How can he be creative of sorting out this method.
It isn't really a good method to use for some cases,
but I can't deny that it's one of the most creative methods I learned.!
Impressive, isn't it?
If you don't believe on the method, create some question and try it yourself.