One of the boys in the group responded, “That’s so smart! That’s so smart! That’s what we should do!” Complex Instruction (CI) is a response to the paradox that group work offers much potential but often creates circumstances where few students seem to learn. CI is a set of ideas and strategies that address the problems that confound group work, but that create powerful learning for children. This book offers guidance to readers on how to use these strategies and ideas. The authors describe the lessons they learned using group work, explain how complex instruction helps unsuccessful students and analyse how to design assignments that support group learning - using group-worthy tasks - giving readers examples of good tasks and help in adapting math problems from their own curricula.