4,500 kilograms. Mathematics is a discipline that studies the concepts of quantity, structure, change, space and information, and belongs to a formal science from a certain point of view. According to the relevant information of this topic, 1 kg is equal to 1000 g, 4,500kg is equal to 4,500,000g, and 4,500,000g is greater than 5,400g, so 4,500kg is big. This subject also plays an irreplaceable role in the development of human history and social life, and is also an indispensable basic tool for studying and studying modern science and technology.