In previous units, students put together pattern blocks to form larger shapes and filled in puzzles. They counted groups of up to 20 objects and images and wrote numbers to record their count. Students use only one kind of pattern block to fill in puzzles and eventually create given shapes without using outlines, which requires students to think informally about the attributes of shapes. Students need to change the orientation of the pattern blocks and align the sides of the pattern blocks. Students may be able to visualize how to turn or flip the shape to fill a particular space or may need to use trial and error. In both activities, students count and write a number to record how many pattern blocks they used.