You probably already know that exercising your brain makes you smarter. Lots of things you do in school, like learning how to speak (or read) a foreign language, how to play a musical instrument or even how to do something in a new way (like partial products multiplication or partial quotients division, for example!) are ways you already train the brain. Just like physical exercise though, the key is CONSISTENCY.
Susanne Jaeggi from the University of Michigan says, “If you go jogging every day, you kind of train your very basic cardiovascular system.” When your cardiovascular system is strong that makes things from walking stairs to bicycling easier. When it comes to our brain, Jaeggi says, “Our basic working memory capacity that we exercise then tends to spread out in all other areas that rely on this working memory capacity.” More info: Brain "Boot Camp" makes you smarter
Here is an interesting game you can play right now to exercise your brain:
Try this: Calculate your brain age (I tried it - I have the brain of a 34-year-old!)
There are also some good ones to try at Fitbrains.com