Identify all sets to which each number belongs.

1) 14

2) 1 and 5/9

3) 3.141516 ...

14 is a positive integer, then it belongs to the set of natural numbers.

1 and 5/9 are rational numbers. The second is already a fraction and the first one, 1, is a natural number, but all the natural numbers can be written as the result of a fraction. For example: 1=6/6.

About the last number, I don't know if it's written correctly. That should be pi maybe, that is 3.14159 ... In that case it's an irrational number.

Irrational numbers are all those real numbers that are not rational.

In general you have that:

ℕ ⊂ ℤ ⊂ ℚ ⊂ ℝ

ℕ. Natural numbers. It's the "smallest" one.

ℤ. Integers. Made with positive and negative natural numbers. Includes the natural numbers then.

ℚ. Rational numbers. Everything that can be written as a fraction. Includes both ℕ and ℤ.

ℝ. Real numbers. Any kind of number, fraction or not.