Source: MOE 2021 O level Additional Maths Syllabus 

The syllabus prepares students adequately for O Level A Math, where a strong foundation in algebraic manipulation skills and mathematical reasoning skills are required. The content is organised into three strands, namely, Algebra, Geometry and Trigonometry, and Calculus. Besides conceptual understanding and skill proficiency explicated in the content strand, the development of process skills, namely, reasoning, communication and connections, thinking skills and heuristics, and applications and modelling are also emphasised. The O-Level Additional Mathematics syllabus assumes knowledge of O-Level Mathematics.