First graders construct arguments using concrete illustrations referents, such as objects, pictures, drawings, and actions

First graders construct arguments using concrete illustrations referents, such as objects, pictures, drawings, and actions. They also practice their mathematical communication skills as they participate in mathematical discussions involving questions like, “How did you get that?” Explain your thinking, “Why is that true?” They not only explain their own thinking, but listen to others’ explanations. They decide if the explanations make sense and ask questions for clarity.