The relevance of mental math skills in the UPSC examination lies in their contribution to solving numerical questions quickly and accurately. Precise calculations are often required in subjects like Economics and Statistics. Developing these skills can aid in answering questions related to data interpretation, which is crucial in the Preliminary exam. Moreover, mental math helps in managing time efficiently, enabling candidates to channel their efforts towards more complex or qualitative issues during the examination. In essence, strong mental math abilities enhance overall performance.