This math topic focuses on calculating a percentage reduction of a number using 10% multiples. It introduces and practices the concept of finding new values after reducing the original numbers by specific percentage amounts, such as 10%, 50%, 70%, 90%, and even 100%. Learners are provided with the initial computation of 10% of various numbers and then asked to determine the remaining amount after the reduction. Multiple-choice questions are used to assess understanding of percentage reductions.