It's Autumn. Let's Learn! is a non-fiction picture book designed to introduce early numeracy concepts to children aged 3-5 through familiar seasonal contexts. Written by a mathematics teacher and parent, the book focuses on developing number sense through observation and exploration rather than rote memorisation. Key mathematical concepts include counting to 10, conceptual subitising, relative magnitude (more, fewer, the same), pattern recognition, and introductory operations. Clear, high-contrast illustrations and purposeful visual design support focus and reduce cognitive load, while structured progression encourages discussion, shared reading, and conceptual understanding. Suitable for early childhood educators, homeschool settings, and families, this title forms the first book in a seasonal series intended to build confidence, curiosity, and foundational mathematical thinking in the early years.