Is 5/8 a irrational number?

No 5/8 is a rational numbe.

Irrational means a number cannot be written as a ratio or simple fraction.

Examples of this are π, √2, repeating decimals, etc.

Rational means a number can be written as a ratio or simple fraction.

Examples of this are integers, fractions like 1/3, 86/100, percents, √4, etc.

5/8 is rational because it is a simple fraction and is another way of writing the ratio 5:8.

So no, 5/8 is not an irrational number.