Do you agree with Mark's reasoning? Is he correct that 2 is a rational number? Explain your answer.

Well, I don't know Mark's reasoning, but the square root of 2 is not a rational number. A rational number is a number that can be represented by a fraction - its decimal form must either be finite (have an end) or repeat (for example, 1/3 or. 3333333 ...). The square root of 2 is infinite and cannot be written as a fraction, so it's not rational.