Here are the numbers classified as rational or irrational:

1. 56 - Rational (it can be expressed as $\frac{56}{1}$)
2. $\sqrt{11}$ - Irrational (square root of a non-perfect square is irrational)
3. 6.565656… - Rational (repeating decimals are rational numbers)
4. 0.23 - Rational (terminating decimal, can be written as $\frac{23}{100}$)
5. 0.32416… - Irrational (non-repeating, non-terminating decimal)
6. −538 - Rational (it can be expressed as $\frac{-538}{1}$)

Thus, the rational numbers are:
56, 6.565656…, 0.23, −538

Would you like more details or have any questions?

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Here are 5 related questions for further practice:

1. Is $\pi$ a rational or irrational number?
2. Can $0.333…$ be classified as a rational number? Why?
3. How do you express a repeating decimal as a fraction?
4. Are negative integers considered rational numbers? Explain.
5. What is the difference between terminating and non-terminating decimals?

Tip: Rational numbers can always be written as a fraction of two integers, where the denominator is non-zero.