Answer: Everything but "irrational number"
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Explanation:
The number 245 is a natural number since the set of natural numbers is {1, 2, 3, 4, 5, 6, ...} basically the set of counting numbers. More technically, the set of natural numbers is the set of positive whole numbers.
The number 245 is also an integer. It does not have any decimal or fractional parts. The set of integers includes negative whole numbers as well.
The number 245 is a whole number for similar reasoning as it being an integer.
The number 245 is a rational number. Why? Because we can write 245 as 245/1. In other words, 245 = 245/1. Because we can form a fraction of two integers, this shows us 245 is rational. Note: 0 cannot be in the denominator.
The number 245 is NOT an irrational. If a number is rational, then it cannot be irrational. The very definition of "irrational" means "not rational". An example of an irrational number is sqrt(2). We cannot write this as a fraction of two integers.
The number 245 is a real number. If you haven't learned about complex numbers yet, then every number you encounter is a real number.
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To summarize, 245 is a natural number, a whole number, an integer, a rational number, and a real number.
A much shorter way to say this is "everything but irrational" since irrational is the only non-answer.
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