This math topic focuses on calculating the percentage tip given for meals, based on the difference between the payment made and the original cost of the meal. The problems are practical scenarios that require finding the percentage increase from the original price to the paid price. Each question provides multiple-choice answers, which requires one to understand and apply the concept of percentage calculation in real-life contexts like dining and tipping. The problems use multiples of 10% to simplify calculations. This is part of an introductory unit on percentages.