At the end of this chapter, the student should be able to:

• Apply Euclid's division lemma to two numbers.
• Find the HCF of two numbers using Euclid's algorithm.
• Find the HCF and LCM using prime factorisation.
• Prove the irrationality of a number using  Fundamental Theorem of Arithmetic.
• Find when is the decimal expansion of a rational number is terminating/ non terminating repeating.