This is one of my favorite activities for the first few weeks of school.
In math, knowing about the net of a shape and the 3D version of the shape is very important. This is a great way to incorporate the net and 3D version of a cube into getting to know your students.
Have them fill out the boxes and color them if you would like. Then, they can follow the instructions on the bottom of the page which tells them to cut only the outside, fold the tabs, and then fold each solid line so it comes together to form a 3-D cube.
I always hang these up in my classroom on fishing wire from the ceiling and it makes for a great decoration for parents to look at on meet the teacher night.