Learning mathematics is like studying a foreign language. At first it is hard, but eventually, it gets progressively easier. A lot of concepts in mathematics are inter-related, so knowing one helps understand many others. However, it has been known for a long time, through many descriptive studies that have been undertaken since the 1970s, that mathematics has been unpopular and disliked. Namely, steps required for learning mathematics, such as “Make sure you have at least an hour a day to dedicate to learning mathematics. Progress through the levels of mathematics. Practice with many problems.” are demanding for many students. In this paper, we present a methodology for learning elementary-school mathematics online. It is supported by a decisionmaking system, based on evolutionary computation, which leads a student in selecting an optimal subset of math items to effectively upgrade the knowledge.