How do you multiply rational numbers?

To multiply rational numbers, simply multiply the numerators (the top numbers) together and the denominators (the bottom numbers) together. For example, to multiply (\frac{a}{b}) and (\frac{c}{d}), you calculate (\frac{a \times c}{b \times d}). If possible, simplify the resulting fraction by finding the greatest common divisor of the numerator and denominator.