Advancement of self-regulation during complex problem solving and the development of strategical reasoning are among the central educational goals linked to 21st century skills. In this paper we introduce the notion of "Stepped Tasks", which are specially designed in Top-Down structure to achieve these goals in mathematics instruction. The paper presents examples of Stepped Tasks and explains their structure. We argue that Stepped Tasks encourage teachers' instructional practices that integrate varying the level of mathematical challenge according to the students' needs. We outline the accompanying research and argue that instructional practices associated with implementation of the Stepped Tasks in top-down structure require major didactical change. While aimed at self-regulated learning, Stepped Tasks appear to be useful in cooperative learning settings as well, and teachers use these tasks in a bottom-up structure in introductory lessons. The variations are also linked to the distinction between teacher-directed and student-regulated modes of implementation of Stepped Tasks.