The problem of quantity is the problem of identifying what about the physical world explains why it can be so well represented with mathematical entities. I introduce quantitative primitivism, the dominant position in the literature, which only offers a partial solution to the problem of quantity. I argue that a reductive account of quantitativeness provides a full solution to the problem, and describe two reductive accounts in the literature. Sections 3 and 4 discusses some of the unique metaphysical consequences of reductive accounts of quantity, including a novel dissolution to the longstanding absolutist/comparativist debate.