What do numbers represent in the poem, On Turning Ten?

Numbers symbolize specific milestones and are given particular significance throughout the poem. Despite the adage “age is just a number,” the speaker has fixated on turning “the first big number” (Line 27). In the second stanza, they reminisce about the defining features of each year: “the perfect simplicity” of one (Line 10), “the beautiful complexity” of two (Line 11), and the adventures of each passing year: “At seven I was a soldier, at nine a prince” (Line 16). The ascension of the numbers give the poem a sense of movement and inevitability.