Division and Multiplication in Rational Numbers

This lecture covers the resolution of division problems in rational numbers by showing the existence and uniqueness of the quotient of two rational numbers. It also explains that in rational numbers, division is equivalent to multiplying by the inverse. Furthermore, it delves into the extension of addition in rational numbers from integers, ensuring that the sum of two fractions with the same denominator is well-defined. The lecture concludes by illustrating the method of simplifying fractions and performing 'cross-cancellations' during multiplication.