The purpose of this How Many Do You See? is for students to use what they know about place value representations to describe and compare the images they see. In the Synthesis, students describe how the number of blocks stays the same (6 of one unit, 4 of the other), but the value that the blocks represent changes dramatically. When students connect these differences to differences in the place value of the digits in the three-digit numbers the diagrams represent, they look for and make sense of structure (MP7).