What is a SURD? An irrational nth root. Any mathematical expression (square root, cube root or higher root) which cannot be written as a common fraction
An irrational number isAny real number that cannot be expressed as a ratio a/b, where a and b are integers and b is non-zero.Informally An irrational number cannot be represented as a simple (common) fraction. Irrational numbers are those real numbers that cannot be represented as terminating or repeating decimals.
A simple fraction (common fraction / vulgar fraction) is A rational number written as a/b Where a and b are both integers The denominator (b) cannot be zero Simple fractions can be positive or negative, proper, or improper