The 'Grammar point' in Lesson 1 states, 'When -ing verbs are used to begin or complete sentences (i.e. used as subjects or objects), they have nominal function (function of a noun) and they are called gerund.'
Class 6 › English Grammar and Composition › Chapter 5: The -ing form of Verb: Gerund & Participle › Topic: Gerund as subject of a sentence
Aligned to the NCTB national curriculum.