Generally a math talk that incorporates of students to provides a task or pose a problem that is accessible at multiple levels.
Collaborative work can take many forms. Students will have opportunities to work problems out together, make conjectures, and critique one another's reasoning. Given tasks will require discussion, problem-solving, and testing of theories. The teacher will be conferencing with groups to provide scaffolding to help students apply new learning.
Opportunity to debrief, journal, have class discussion, and/or do a quick assessment.