The Enders Game by Orson Scott,
The book is a 1985 military science fiction novel. The novel presents an imperiled mankind after two conflicts with the Formics, an insect alien species called the buggers. They are looking after a 6 year old boy named Ender with a monitor and they think he will be a good recruit for their battle school. They take him when they think he is ready he finds his enemy fast after he brakes his arm and he finds he is good at the games and shows the bully who is boss. The boys have it rough in the beginning because they miss their family and friends. They only have one thing that they can do for fun and that’s the games but Ender finds out how to play the games by watching and he gets good. And he will try to become a great commander and beat the buggers.