Number properties Natural numbers Natural numbers: Practice identifying if numbers are natural numbers. Level game: 4th, 5th and 6th grade Math games recommended for You: Real numbers Integers Rational numbers Irrational numbers 4th grade5th grade6th grade Share this Practice math games: Centimeters to meters Order of operations with brackets (easy) Adding and subtracting negative numbers Leave A Comment Cancel reply Save my name, email, and website in this browser for the next time I comment.