On the Number of Rational Numbers: Two Infinite Sides and One Central Element

This paper examines the number of rational numbers from a structural perspective. Rather than revising the standard cardinality result |Q| = ℵ₀, we describe how rational numbers are arranged around zero: as two opposing infinite sides together with a single central element. Every non-zero rational number q has an oppositely signed counterpart −q of equal magnitude. Zero satisfies −0 = 0 and therefore remains the unique fixed point of the opposite-operation. The paper develops this description through finite symmetric sequences, the geometry of the number line, and a set-theoretic decomposition of Q. The result is a structural observation, not a new cardinality theorem.