This math topic focuses on long division, specifically on identifying the first subtraction step in two-step long division problems that result in a remainder. It offers an opportunity to practice digit solving within the context of long division. Through a series of questions, learners are required to discern the missing subtraction value in various division problems, enhancing their understanding of the mechanics of long division. Each problem presents multiple choices for the missing values, encouraging learners to apply division principles to select the correct answer.