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.
Game expression expansion (14 year old)
Countdown game (14 year old)
Quiz on the Pythagorean theorem (14 year old)
Irreducible fraction of an expression (14 year old)
Factorization game using remarkable identities (14 year old)
Quiz solving first degree equations (14 year old)
Quiz on algebraic calculus (14 year old)