This website offers many math games that allow you to practice arithmetic calculations, here is a selection of the best online math games 14 year old available.
Factorization game using remarkable identities (14 year old)
Quiz on the Pythagorean theorem (14 year old)
Quiz solving first degree equations (14 year old)
Countdown game (14 year old)
Game expression expansion (14 year old)
Quiz on algebraic calculus (14 year old)
Irreducible fraction of an expression (14 year old)