This math topic focuses on solving for the count (number of items) in a dataset given the sum and the mean of the data. It tests the ability to apply the formula for finding the mean: mean = sum / count, by rearranging it to find the count: count = sum / mean. These skills are part of a broader unit on probability and statistics, particularly focusing on the concepts of mean, median, and mode. The topic contains multiple-choice questions that require solving different scenarios to find how many numbers are present in sets with specified sums and means.